[嵌入式开发模块]MC9S12XEP100 SCI(UART)驱动程序2 - 基于uCOS-II

淩亂°似流年 2022-06-13 02:30 237阅读 0赞

忙着毕设，很久没有写文章了，终于答辩完了，得了个校优秀毕业设计。毕设做的是个智能接口模块，用一周时间入门了MC9S12XEP100的开发，又用一周时间入门了uC/OS-II嵌入式操作系统，在做毕设的过程中学到了很多，现在把一些工具发上来分享。

--------------------

首先先发一个自己封装的MC9S12XEP100的SCI模块(也就是UART模块)的驱动。这些代码参考了 Li Yuan [http://blog.csdn.net/liyuanbhu/article/details/7764851][http_blog.csdn.net_liyuanbhu_article_details_7764851] 的代码，整个代码风格是按照uCOS-II操作系统源码的风格来写的，在此表示感谢。  
目前还不是特别完整完善，但基本使用是没有问题了。  
在[上一章][Link 1]中已经发了硬件驱动部分，这里发下基于uCOS-II嵌入式操作系统的驱动部分以及顺便说下怎么用。  
首先要记得到[上一章][Link 1]中把两个文件存了，顺便还要把.h文件中的

SCI\_UCOS\_MODULE\_ENABLE 后面改为 TRUE 以开启RTOS(嵌入式操作系统)驱动部分。

目前这个版本已经支持所有8个SCI口了。  
首先是按照uCOS-II操作系统的要求写的中断服务程序。

;********************************************************************************************************
    ;                                               uC/OS-II
    ;                                         The Real-Time Kernel
    ;
    ;                         (c) Copyright 2002, Jean J. Labrosse, Weston, FL
    ;                                          All Rights Reserved
    ;
    ;
    ;                                       PAGED S12X Specific code
    ;                                            (CODEWARRIOR)
    ;
    ; File         : SCI_uCos.s
    ; By           : Lin Shijun(http://blog.csdn.net/lin_strong)
    ;
    ; Notes        : THIS FILE *MUST* BE LINKED INTO NON_BANKED MEMORY! 这个文件必须放在非分页内存中
    ;                    modified according to uC/OS-II's example.  依据uC/OS-II的模版修改。
    ;********************************************************************************************************
    
    NON_BANKED:       section
    
    
    ;********************************************************************************************************
    ;                                           I/O PORT ADDRESSES   I/O口地址
    ;********************************************************************************************************
    
    PPAGE:            equ    $0015         ; Addres of PPAGE register (assuming MC9S12XEP100 part)
    RPAGE:            equ    $0016         ; Addres of RPAGE register (assuming MC9S12XEP100 part)
    EPAGE:            equ    $0017         ; Addres of EPAGE register (assuming MC9S12XEP100 part)
    GPAGE:            equ    $0010         ; Addres of GPAGE register (assuming MC9S12XEP100 part)
    
    
    ;********************************************************************************************************
    ;                                          PUBLIC DECLARATIONS   公开声明
    ;********************************************************************************************************
    
        xdef   SCI0_RxTxISR
        xdef   SCI1_RxTxISR
        xdef   SCI2_RxTxISR
        xdef   SCI3_RxTxISR
        xdef   SCI4_RxTxISR
        xdef   SCI5_RxTxISR
        xdef   SCI6_RxTxISR
        xdef   SCI7_RxTxISR
    
    ;********************************************************************************************************
    ;                                         EXTERNAL DECLARATIONS  外部声明
    ;********************************************************************************************************
    
        xref   OSIntExit
        xref   OSIntNesting
        xref   OSTCBCur
    
        xref   SCI0_ISR_Handler
        xref   SCI1_ISR_Handler
        xref   SCI2_ISR_Handler
        xref   SCI3_ISR_Handler
        xref   SCI4_ISR_Handler
        xref   SCI5_ISR_Handler
        xref   SCI6_ISR_Handler
        xref   SCI7_ISR_Handler
    
    
    ;********************************************************************************************************
    ;                                           SCI RxTx ISR
    ;
    ; Description : This routine is the uC/Probe RxTx interrupt service routine
    ;
    ; Arguments   : none
    ;
    ; Notes       : 1) All USER interrupts should be modeled EXACTLY like this where the only
    ;                  line to be modified is the call to your ISR_Handler and perhaps the call to
    ;                  the label name SCI0_ISR_Handler.
    ;********************************************************************************************************
    
    SCI0_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI0_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    SCI0_RxTxISR1:
        call   SCI0_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.
    
    SCI1_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI1_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    
    SCI1_RxTxISR1:
        call   SCI1_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.
    
    SCI2_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI2_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    
    SCI2_RxTxISR1:
        call   SCI2_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.
    
    SCI3_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI3_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    
    SCI3_RxTxISR1:
        call   SCI3_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.
    
    SCI4_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI4_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    
    SCI4_RxTxISR1:
        call   SCI4_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.
    
    
    SCI5_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI5_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    
    SCI5_RxTxISR1:
        call   SCI5_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.
    
    SCI6_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI6_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    
    SCI6_RxTxISR1:
        call   SCI6_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.
    
    
    SCI7_RxTxISR:
        ldaa   GPAGE                       ; Get current value of GPAGE register
        psha                               ; Push GPAGE register onto current task's stack
    
        ldaa   EPAGE                       ; Get current value of EPAGE register
        psha                               ; Push EPAGE register onto current task's stack
    
        ldaa   RPAGE                       ; Get current value of RPAGE register
        psha                               ; Push RPAGE register onto current task's stack
    
        ldaa   PPAGE                       ; Get current value of PPAGE register
        psha                               ; Push PPAGE register onto current task's stack
    
        inc    OSIntNesting                ; Notify uC/OS-II about ISR
    
        ldab   OSIntNesting                ; if (OSIntNesting == 1) {
        
        cmpb   #$01
        bne    SCI7_RxTxISR1
    
        ldy    OSTCBCur                    ;     OSTCBCur->OSTCBStkPtr = Stack Pointer
        sts    0,y                         ; }
    
    
    SCI7_RxTxISR1:
        call   SCI7_ISR_Handler  ; Call TxRx ISR handler. (See SCI_uCos.c)
    
    ;   cli                               ; Optionally enable interrupts to allow interrupt nesting
    
        call   OSIntExit                  ; Notify uC/OS-II about end of ISR, a context switch may occur from within OSIntExit().
    
        pula                               ; Get value of PPAGE register
        staa   PPAGE                       ; Store into CPU's PPAGE register
    
        pula                               ; Get value of RPAGE register
        staa   RPAGE                       ; Store into CPU's RPAGE register
    
        pula                               ; Get value of EPAGE register
        staa   EPAGE                       ; Store into CPU's EPAGE register
    
        pula                               ; Get value of GPAGE register
        staa   GPAGE                       ; Store into CPU's GPAGE register
    
        rti                               ; Return from interrupt to interrupted task.

要记得修改中断向量表把用到的端口的ISR分别指向其中断地址，如SCI0\_RxTxISR指向0xFFD6、SCI1\_RxTxISR1指向0xFFD4，也就是SCI0和SCI1的中断地址。

然后是.c文件：

/*
    *******************************************************************************************
    *
    *
    *                    SCI(Serial Communication Interface)  Buffered Serial I/O     
    *                                   Freescale MC9S12XEP100
    *                           飞思卡尔   MC9S12XEP100  SCI支持包
    *
    * File : SCI_uCos.c
    * By   : Lin Shijun(http://blog.csdn.net/lin_strong)
    * Date:  2018/02/23
    * version: V2.2
    * History: 2017/04/24  V1.0   the prototype of SCI_uCOS,only support SCI0 and SCI1
    *          2017/07/20  V2.0   update the module to support the SCI0 to SCI7
    *          2017/10/27  V2.1   fix a bug: when disable a port between two active port,the upper one can't work.
    *                             this is due to the statment: 
    *                                  for(port = 0;port < 8 && isSCIEnable(port);port++)
    *                             in SCI_BufferInit().
    *                             the judgment statment port < 8 && isSCIEnable(port) will jump out the init loop 
    *                               the first time meet the first disabled SCI port.
    *          2018/02/23  V2.2  a. optimize the struct referencing to the register
    *                            b. delete some configuration marco, because the unused function will not be linked
    *                               in the project, so there is no need to hide the function.
    *                            c. add more error check.
    *                            d. add a marco(SCI_ARGUMENT_CHECK_EN) to turn off argument check for saving code.
    *                            e. add the support for define buffer in paged addressing area.
    *                            f. use semaphore in replace of the origional mutex, so the user don't need to take
    *                               care of the priority thing. The cost is the possibility of priority inversion.
    *                               But I think it's worth it.
    * NOTE(s): 1.refer to Li Yuan's  (http://blog.csdn.net/liyuanbhu/article/details/7768914)
    *             and 
    *            uCOS-II's Code
    *          2.记得把SCI_uCOS.s中的SCIx_RxTxISR中断服务程序指向对应的中断向量地址
    *          3.如果你想要把缓冲区定义到分页区或者全局地址的话，参考第210行。
    ********************************************************************************************
    */
    
    /*
    ********************************************************************************************
    *                                   INCLUDES
    ********************************************************************************************
    */
    #include "SCI_def.h"
    #if(SCI_MODULE_ENABLE == TRUE && SCI_UCOS_MODULE_ENABLE == TRUE)
    
    #include <string.h>
    #include "RingQueue.h"
    
    /* 
    *********************************************************************************************
    *                                    DATA TYPES 
    *********************************************************************************************
    */
    
    typedef struct{
        INT8U port;                                 /* Hold the port number         */
        OS_EVENT  *RingBufRxSem;                    /* Pointer to Rx semaphore      */  
        RING_QUEUE*  RingBufRx;                     /* Ring buffer character storage (Rx) */  
        OS_EVENT  *RingBufTxMutex;                  /* Pointer to Tx MUTUAL semaphore     */
        OS_EVENT  *RingBufTxSem;                    /* Pointer to Tx semaphore          */  
        RING_QUEUE*  RingBufTx;                     /* Ring buffer character storage (Tx) */  
    } SCI_RING_BUF, *pSCI_RING_BUF;
    
    /*
    ****************************************************************************************
    *                                 CONSTANT 
    ****************************************************************************************
    */
    // Flag of SCI enable.
    #define EnableFlag ((SCI0_UCOS_CODE_EN << 0) | (SCI1_UCOS_CODE_EN << 1) | (SCI2_UCOS_CODE_EN << 2) | \
                         (SCI3_UCOS_CODE_EN << 3) | (SCI4_UCOS_CODE_EN << 4) | (SCI5_UCOS_CODE_EN << 5) | \
                         (SCI6_UCOS_CODE_EN << 6) | (SCI7_UCOS_CODE_EN << 7))
    #define isSCIEnable(port) ((EnableFlag >> port) & 0x01)
    
    // const of RxBuffer Sizes
    #if(SCI0_RX_BUFFER_SIZE < 256 && SCI1_RX_BUFFER_SIZE < 256 && SCI2_RX_BUFFER_SIZE < 256 && \
        SCI3_RX_BUFFER_SIZE < 256 && SCI4_RX_BUFFER_SIZE < 256 && SCI5_RX_BUFFER_SIZE < 256 && \
        SCI6_RX_BUFFER_SIZE < 256 && SCI7_RX_BUFFER_SIZE < 256)
       #define RxSizeArrType INT8U
    #else
       #define RxSizeArrType INT16U
    #endif
    
    static const RxSizeArrType SCIRxBufferSize[]={
         SCI0_RX_BUFFER_SIZE,
         SCI1_RX_BUFFER_SIZE,
         SCI2_RX_BUFFER_SIZE,
         SCI3_RX_BUFFER_SIZE,
         SCI4_RX_BUFFER_SIZE,
         SCI5_RX_BUFFER_SIZE,
         SCI6_RX_BUFFER_SIZE,
         SCI7_RX_BUFFER_SIZE,
     };
    #define SCIRxBufSize(port) SCIRxBufferSize[port]
    #define isSCIRxEnable(port) (SCIRxBufferSize[port] > 0)
    
    // const of TxBuffer Sizes
    #if(SCI0_TX_BUFFER_SIZE < 256 && SCI1_TX_BUFFER_SIZE < 256 && SCI2_TX_BUFFER_SIZE < 256 && SCI3_TX_BUFFER_SIZE < 256 \
     && SCI4_TX_BUFFER_SIZE < 256 && SCI5_TX_BUFFER_SIZE < 256 && SCI6_TX_BUFFER_SIZE < 256 && SCI7_TX_BUFFER_SIZE < 256)
     #define TxSizeArrType INT8U
    #else
     #define TxSizeArrType INT16U
    #endif
    
    static const TxSizeArrType SCITxBufferSize[]={
         SCI0_TX_BUFFER_SIZE,
         SCI1_TX_BUFFER_SIZE,
         SCI2_TX_BUFFER_SIZE,
         SCI3_TX_BUFFER_SIZE,
         SCI4_TX_BUFFER_SIZE,
         SCI5_TX_BUFFER_SIZE,
         SCI6_TX_BUFFER_SIZE,
         SCI7_TX_BUFFER_SIZE,
     };
    #define SCITxBufSize(port) SCITxBufferSize[port]
    #define isSCITxEnable(port) (SCITxBufferSize[port] > 0)
    
    #define SCI_RX_BUFFER_SIZE_SUM (SCI0_RX_BUFFER_SIZE + SCI1_RX_BUFFER_SIZE + SCI2_RX_BUFFER_SIZE + SCI3_RX_BUFFER_SIZE \
                                    + SCI4_RX_BUFFER_SIZE + SCI5_RX_BUFFER_SIZE + SCI6_RX_BUFFER_SIZE + SCI7_RX_BUFFER_SIZE)
    #define SCI_TX_BUFFER_SIZE_SUM (SCI0_TX_BUFFER_SIZE + SCI1_TX_BUFFER_SIZE + SCI2_TX_BUFFER_SIZE + SCI3_TX_BUFFER_SIZE \
                                    + SCI4_TX_BUFFER_SIZE + SCI5_TX_BUFFER_SIZE + SCI6_TX_BUFFER_SIZE + SCI7_TX_BUFFER_SIZE)
    #define SCI_BUFFER_SIZE_SUM (SCI_RX_BUFFER_SIZE_SUM + SCI_TX_BUFFER_SIZE_SUM)
    
    #define SCI_RX_BUFFERS_COUNT ((SCI0_RX_BUFFER_SIZE>0) + (SCI1_RX_BUFFER_SIZE>0) + (SCI2_RX_BUFFER_SIZE>0) + \
                                 (SCI3_RX_BUFFER_SIZE>0) + (SCI4_RX_BUFFER_SIZE>0) + (SCI5_RX_BUFFER_SIZE>0) + \
                                 (SCI6_RX_BUFFER_SIZE>0) + (SCI7_RX_BUFFER_SIZE>0))
    #define SCI_TX_BUFFERS_COUNT ((SCI0_TX_BUFFER_SIZE>0) + (SCI1_TX_BUFFER_SIZE>0) + (SCI2_TX_BUFFER_SIZE>0) + \
                                 (SCI3_TX_BUFFER_SIZE>0) + (SCI4_TX_BUFFER_SIZE>0) + (SCI5_TX_BUFFER_SIZE>0) + \
                                 (SCI6_TX_BUFFER_SIZE>0)) + (SCI7_TX_BUFFER_SIZE>0)
    #define SCI_BUFFERS_COUNT (SCI_RX_BUFFERS_COUNT + SCI_TX_BUFFERS_COUNT)
    
    #define SCI_RING_QUEUE_COUNT SCI_BUFFERS_COUNT
    /*
    ****************************************************************************************
    *                                 GLOBAL VARIABLES  
    ****************************************************************************************
    */
    
    #define SCI_RING_BUFS_COUNT SCI0_UCOS_CODE_EN + SCI1_UCOS_CODE_EN + SCI2_UCOS_CODE_EN + SCI3_UCOS_CODE_EN + \
                               SCI4_UCOS_CODE_EN + SCI5_UCOS_CODE_EN + SCI6_UCOS_CODE_EN + SCI7_UCOS_CODE_EN
    
    SCI_RING_BUF SCIBufs[SCI_RING_BUFS_COUNT];
    
    SCI_RING_BUF * const Ptr_SCIBuf[] = {
      #if(SCI0_UCOS_CODE_EN == TRUE)
         &SCIBufs[0],
      #else
         NULL,
      #endif
      #if(SCI1_UCOS_CODE_EN == TRUE)
         &SCIBufs[SCI0_UCOS_CODE_EN],
      #else
         NULL,
      #endif
      #if(SCI2_UCOS_CODE_EN == TRUE)
         &SCIBufs[SCI0_UCOS_CODE_EN + SCI1_UCOS_CODE_EN],
      #else
         NULL,
      #endif
      #if(SCI3_UCOS_CODE_EN == TRUE)
         &SCIBufs[SCI0_UCOS_CODE_EN + SCI1_UCOS_CODE_EN + SCI2_UCOS_CODE_EN],
      #else
         NULL,
      #endif
      #if(SCI4_UCOS_CODE_EN == TRUE)
         &SCIBufs[SCI0_UCOS_CODE_EN + SCI1_UCOS_CODE_EN + SCI2_UCOS_CODE_EN + SCI3_UCOS_CODE_EN],
      #else
         NULL,
      #endif
      #if(SCI5_UCOS_CODE_EN == TRUE)
         &SCIBufs[SCI0_UCOS_CODE_EN + SCI1_UCOS_CODE_EN + SCI2_UCOS_CODE_EN + SCI3_UCOS_CODE_EN + SCI4_UCOS_CODE_EN],
      #else
         NULL,
      #endif
      #if(SCI6_UCOS_CODE_EN == TRUE)
         &SCIBufs[SCI0_UCOS_CODE_EN + SCI1_UCOS_CODE_EN + SCI2_UCOS_CODE_EN + SCI3_UCOS_CODE_EN + SCI4_UCOS_CODE_EN \
          + SCI5_UCOS_CODE_EN],
      #else
         NULL,
      #endif
      #if(SCI7_UCOS_CODE_EN == TRUE)
         &SCIBufs[SCI0_UCOS_CODE_EN + SCI1_UCOS_CODE_EN + SCI2_UCOS_CODE_EN + SCI3_UCOS_CODE_EN + SCI4_UCOS_CODE_EN \
         + SCI5_UCOS_CODE_EN + SCI6_UCOS_CODE_EN],
      #else
         NULL,
      #endif
    };
    #define pSCIBuf(port) Ptr_SCIBuf[port]
    
    /*
    *********************************************************************************************
    *                                 LOCAL VARIABLES  
    *********************************************************************************************
    */
    
    static union{
        byte FLAG;
        struct {
        byte Inited   :1;           //Initialized Flag 
        byte          :1;                                       
        byte          :1;                                       
        byte          :1;                                       
        byte          :1;                                       
        byte          :1;                                       
        byte          :1; 
        byte          :1;                                       
      } Bits;
    } flag = {
       0};
    
    // 所有SCI的所有收发缓冲区其实都在同一个大数组中，每个小块分别由不同的环形队列对象管理即可
    
    #if (SCI_BUFFER_SIZE_SUM > 0)
    // if you want to put buffers in paged RAM，make sure to configure the RQ_ADDRESSING_MODE in RingQueue.h
    // to banked addressing mode or global addressing mode.
    // then, uncomment the two #pragma statement will define the buffer in the paged address.
    // 如果你想要把缓冲区放在分页RAM区的话，一定要将RingQueue.h中的寻址模式改为分页区寻址或全局寻址，否则编译器
    // 无法生成正确的访问代码。
    // 然后，取消下面两个pragma注释就会把缓冲区定义到分页区RAM(总大小不能大于4KB)，详情请参考相关资料，可以到我的博客找。
    //#pragma DATA_SEG __RPAGE_SEG PAGED_RAM
      static INT8U SCIBuffer[SCI_BUFFER_SIZE_SUM];
    //#pragma DATA_SEG DEFAULT
    #else
       static INT8U *SCIBuffer = NULL;
    #endif
    
    
    
    // 管理SCI的所有环形队列对象都在一个数组中
    #if (SCI_RING_QUEUE_COUNT > 0)
       static RING_QUEUE SCIRingQueues[SCI_BUFFERS_COUNT];
    #else
       static RING_QUEUE* SCIRingQueues = NULL;
    #endif
    #define pSCI_RingBufRx(port) (pSCIBuf(port)->RingBufRx)
    #define pSCI_RingBufTx(port) (pSCIBuf(port)->RingBufTx)
    
    /*
    ******************************************************************************************
    *                              LOCAL FUNCTION DECLARE
    ******************************************************************************************
    */
    
    #if(SCI_ARGUMENT_CHECK_EN == TRUE)
      #define argCheck1(cond,err,rVal)   if(cond){*perr = (err); return (rVal);}
      #define argCheck2(cond,rVal)       if(cond){ return (rVal);}
      #define argCheck3(cond)            if(cond){ return ;}
      #define argCheck4(cond,err)        if(cond){*perr = (err); return;}
    #else
      #define argCheck1(cond,err,rVal)
      #define argCheck2(cond,rVal)
      #define argCheck3(cond)
      #define argCheck4(cond,err)
    #endif // of (SCI_ARGUMENT_CHECK_EN == TRUE)
      #define portCheckTx1(err,rVal)    argCheck1(port >= SCI_CNT || !isSCITxEnable(port),err,rVal)
      #define portCheckTx2(rVal)        argCheck2(port >= SCI_CNT || !isSCITxEnable(port),rVal)
      #define portCheckTx3()            argCheck3(port >= SCI_CNT || !isSCITxEnable(port))
      #define portCheckTx4(err)         argCheck4(port >= SCI_CNT || !isSCITxEnable(port),err)
      #define portCheckRx1(err,rVal)    argCheck1(port >= SCI_CNT || !isSCIRxEnable(port),err,rVal)
      #define portCheckRx2(rVal)        argCheck2(port >= SCI_CNT || !isSCIRxEnable(port),rVal)
      #define portCheckRx3()            argCheck3(port >= SCI_CNT || !isSCIRxEnable(port))
      #define portCheckRx4(err)         argCheck4(port >= SCI_CNT || !isSCIRxEnable(port),err)
    
    #pragma CODE_SEG __NEAR_SEG NON_BANKED 
    // 本地函数不做参数检查，由外部接口函数负责参数的正确
    // 内部用来放字符到发送缓冲区, 返回的是SemPend的错误，默认RingQueueIn是不可能出错的(因为有信号量保证有空间可用)
    static INT8U _SCI_TxPutCharB(pSCI_RING_BUF pbuf, INT8U c, INT16U timeout);
    // 这个函数由Rx ISR来插入一个字符到缓冲区内
    static void  _SCI_RxPutCharB (INT8U port, INT8U c);
    // 这个函数由Tx ISR调用来从Tx缓冲区内提取下一个字符.如果发现没有字符可以提取了,perr就返回SCI_TX_EMPTY.
    //   这是用来通知Tx ISR禁止中断的。
    static INT8U _SCI_TxGetCharB (INT8U port, INT8U *perr);
    #pragma CODE_SEG DEFAULT
    
    /*
    ******************************************************************************************
    *                                 SCI_BufferInit()
    *
    * Description :   To initialize the communications module.                         
    *                     初始化通信模型.
    *                 You must call this function before calling any other functions.  
    *                     必须在调用其他函数前调用它.
    * Arguments   : 
    *                       
    * Return:
    *
    *Note(s):
    ******************************************************************************************
    */
    
    void  SCI_BufferInit (void)  
    {  
      SCI_RING_BUF *pSCIRingBuf;    
      INT8U err,port;
      RING_QUEUE* pRingQueue = SCIRingQueues;
      INT8U *__far pBuf = SCIBuffer;    // __far for support SCIBuffer in any address.
    
      // 简单的保护
      if(flag.Bits.Inited) return;
      // Initialize all buffers 
      for(port = 0;port < SCI_CNT;port++){
        if(!isSCIEnable(port))       // continue when the current port is not enable.
          continue;
        pSCIRingBuf = pSCIBuf(port);
        pSCIRingBuf->port = port;
        if(isSCITxEnable(port)) {
          pSCIRingBuf->RingBufTxMutex  = OSSemCreate(1);   // use semaphore as mutex
          pSCIRingBuf->RingBufTxSem = OSSemCreate(SCITxBufSize(port));      
          pSCIRingBuf->RingBufTx = RingQueueInit(pRingQueue++,pBuf,SCITxBufSize(port),&err);
          pBuf += SCITxBufSize(port);
        }
        if(isSCIRxEnable(port)) {
          pSCIRingBuf->RingBufRxSem = OSSemCreate(0);      
          pSCIRingBuf->RingBufRx = RingQueueInit(pRingQueue++,pBuf,SCIRxBufSize(port),&err);
          pBuf += SCIRxBufSize(port);
        }
      }
      flag.Bits.Inited = 1;
    }
    /*
    ******************************************************************************************
    *                                      SCI_GetCharB()
    *
    * Description : To obtain a character from the communications channel.  
    *                  从通信信道中获取一个字符
    *
    * Arguments   : port       port can be SCI0 / SCI1;                  选择端口;
    *               timeout    the amount of time (in clock ticks) that the calling function is willing to ...
    *                          ...wait for a character to arrive.  If you specify a timeout of 0,...
    *                          ...the function will wait forever for a character to arrive.
    *                             调用者最久愿意等待一个字符到达的时钟节拍数,为0表示永久等待.
    *               perr        is a pointer to where an error code will be placed: 用于返回故障码:
    *                               SCI_NO_ERR      if a character has been received          正确收到字符
    *                               SCI_RX_TIMEOUT  if a timeout occurred                     接收超时
    *                               SCI_BAD_CH      if you specify an invalid channel number  通道号错误
    * Return:       The character in the buffer (or 0 if a timeout occurred); 缓冲区内的字符(或者发生了超时);
    * Note(s):
    *******************************************************************************************
    */
    INT8U  SCI_GetCharB (INT8U port, INT16U timeout, INT8U *perr)  
    {
    #if OS_CRITICAL_METHOD == 3                    /* Allocate storage for CPU status register     */  
      OS_CPU_SR  cpu_sr = 0u;  
    #endif  
      INT8U c;  
      INT8U oserr;  
      SCI_RING_BUF *pbuf;
      portCheckRx1(SCI_BAD_CH,0);
      pbuf = pSCIBuf(port);
      OSSemPend(pbuf->RingBufRxSem, timeout, &oserr);  /* Wait for character to arrive             */  
      if (oserr == OS_TIMEOUT)   
      {                                                /* See if characters received within timeout*/  
        *perr = SCI_RX_TIMEOUT;                       /* No, return error code                    */  
        return (0);  
      }   
      else   
      {  
        OS_ENTER_CRITICAL();  
        c = RingQueueOut(pbuf->RingBufRx,&oserr);                   /* Get next one from ring queue.*/
        OS_EXIT_CRITICAL();  
        *perr = SCI_NO_ERR;
        return (c);  
      }  
    } 
    /*
    **********************************************************************************************
    *                                        SCI_PutCharB_Mutex()
    *
    * Description : This function is called by your application to send a character on the communications 
    *                  channel.  The function will wait for the buffer to empty out if the buffer is full. 
    *                  The function returns to your application if the buffer doesn't empty within the specified 
    *                  timeout.  A timeout value of 0 means that the calling function will wait forever for the 
    *                  buffer to empty out.  The character to send is first inserted into the Tx buffer and will 
    *                  be sent by the Tx ISR.  If this is the first character placed into the buffer, the Tx ISR 
    *                  will be enabled.
    *
    *               equal to call:     
    *                  SCI_SendBuf_hold (port, timeout, &perr);
    *                  perr =  SCI_PutCharB(port, INT8U c, INT16U timeout);
    *                  SCI_SendBuf_release(port);
    *
    * Arguments   : port      port can be SCI0 / SCI1;                      选择端口;
    *               c         the character to send;                        要发送的字符;
    *               timeout   is the timeout (in clock ticks) to wait in case the buffer is full.  If you ...
    *                         ...specify a timeout of 0, the function will wait forever for the buffer to empty. 
    *                         在缓冲区满的情况下, 调用者最久愿意等待的时钟节拍数,为0表示永久等待.
    * Return:      SCI_NO_ERR       if the character was placed in the Tx buffer;  
    *                                    字符成功放入Tx缓冲区内;
    *              SCI_TX_TIMEOUT   if the buffer didn't empty or can't access within the specified timeout period;
    *                                    超时后还是没有清空缓冲区或者还无法访问
    *              SCI_BAD_CH       if you specify an invalid channel number  通道号错误
    *              SCI_PEND_ISR     If you called this function from an ISR and the result would lead to a suspension.
    *                                    在ISR中调用了这个函数并且需要等待
    *              SCI_PEND_LOCKED  If you called this function when the scheduler is locked.
    *                                    如果当系统调度器被锁住的时候调用的这个函数
    *              SCI_ERR_UNKNOWN  
    * Note(s): 1. Don't use this function in ISR routine
    *             不要在ISR中使用这个函数
    **********************************************************************************************
    */
    INT8U SCI_PutCharB_Mutex (INT8U port, INT8U c, INT16U timeout)  
    {  
        pSCI_RING_BUF pbuf;  
        INT8U oserr;  
        portCheckTx2(SCI_BAD_CH);
        pbuf = pSCIBuf(port);
        OSSemPend(pbuf->RingBufTxMutex,timeout,&oserr);  /* Wait for the right of using Tx buffer*/
        if(oserr == OS_ERR_NONE){                        /* If get the right then */
          oserr =  _SCI_TxPutCharB(pbuf,c,timeout);      /*  Put INT8U into Tx buffer*/ 
          OSSemPost(pbuf->RingBufTxMutex);               /* Release the the right of use Tx buffer*/  
        }else if (oserr == OS_TIMEOUT)                          /* If Timeout happen */
          return (SCI_TX_TIMEOUT);                      /* Timed out, return error code             */ 
        else if (oserr == OS_ERR_PEND_ISR) 
          return (SCI_PEND_ISR);
        else if (oserr == OS_ERR_PEND_LOCKED)
          return (SCI_PEND_LOCKED);
        else
          return (SCI_ERR_UNKNOWN);
        return (SCI_NO_ERR);  
    }
    /*
    *********************************************************************************************
    *                                        SCI_PutCharsB_Mutex()
    *
    * Description : This function is called by your application to send chars on the communications 
    *                   channel.  The function will wait for the buffer to empty out if the buffer is full. 
    *                   The function returns to your application if the buffer doesn't empty within the specified 
    *                   timeout.  A timeout value of 0 means that the calling function will wait forever for the 
    *                   buffer to empty out.  The character to send is first inserted into the Tx buffer and will 
    *                   be sent by the Tx ISR.  If this is the first character placed into the buffer, the Tx ISR 
    *                   will be enabled. 
    *                        equal to call:     
    *                            SCI_SendBuf_hold (port, timeout, &perr);
    *                            perr =  SCI_PutCharsB(port, INT8U c, INT16U timeout);
    *                            SCI_SendBuf_release(port);
    *
    * Arguments   : port       port can be SCI0 / SCI1;          选择端口;
    *               buf        the buffer;                       要发送的字符;
    *               length     the length of the buffer;        
    *               timeout    is the timeout (in clock ticks) to wait in case the buffer is full.  If you 
    *                             specify a timeout of 0, the function will wait forever for the buffer to empty. 
    *                                  在缓冲区满的情况下, 调用者最久愿意等待的时钟节拍数,为0表示永久等待.
    * Return:      SCI_NO_ERR       if the character was placed in the Tx buffer;  
    *                                    字符成功放入Tx缓冲区内;
    *              SCI_TX_TIMEOUT   if the buffer didn't empty or can't access within the specified timeout period;
    *                                    超时后还是没有清空缓冲区或者还无法访问
    *              SCI_BAD_CH       if you specify an invalid channel number  通道号错误
    *              SCI_PEND_ISR     If you called this function from an ISR and the result would lead to a suspension.
    *                                    在ISR中调用了这个函数并且需要等待
    *              SCI_PEND_LOCKED  If you called this function when the scheduler is locked.
    *                                    如果当系统调度器被锁住的时候调用的这个函数
    *              SCI_ERR_UNKNOWN  
    * Note(s): 1. Don't use this function in ISR routine
    *             不要在ISR中使用这个函数
    ***********************************************************************************************
    */
    INT8U SCI_PutCharsB_Mutex (INT8U port, const INT8U *buf,INT16U length, INT16U timeout) {
        pSCI_RING_BUF pbuf;  
        INT8U oserr;  
        portCheckTx2(SCI_BAD_CH);
        pbuf = pSCIBuf(port);
        OSSemPend(pbuf->RingBufTxMutex,timeout,&oserr);        /* Wait for the right of use Tx buffer*/
        if(oserr == OS_ERR_NONE){
          while(length--){
            oserr =  _SCI_TxPutCharB(pbuf,*buf++,timeout);     /*  Put INT8U into Tx buffer*/ 
            if (oserr != OS_ERR_NONE)                           /* if any err happen */
              break;                                         /* break */ 
            }
          OSSemPost(pbuf->RingBufTxMutex);
        }else if (oserr == OS_TIMEOUT)                          /* If Timeout happen */
          return (SCI_TX_TIMEOUT);                      /* Timed out, return error code             */ 
        else if (oserr == OS_ERR_PEND_ISR) 
          return (SCI_PEND_ISR);
        else if (oserr == OS_ERR_PEND_LOCKED)
          return (SCI_PEND_LOCKED);
        else
          return (SCI_ERR_UNKNOWN);
        return (SCI_NO_ERR);  
    }
    /*
    ********************************************************************************************
    *                                 SCI_PutStringB_Mutex()
    *
    * Description : This function is called by your application to send a string,which ends with '\0', on the communications 
    *                 channel.  The function will wait for the buffer to empty out if the buffer is full. 
    *                 The function returns to your application if the buffer doesn't empty within the specified 
    *                 timeout.  A timeout value of 0 means that the calling function will wait forever for the 
    *                 buffer to empty out.  The character to send is first inserted into the Tx buffer and will 
    *                 be sent by the Tx ISR.  If this is the first character placed into the buffer, the Tx ISR 
    *                 ill be enabled. 
    *
    * Arguments   : port       port can be SCI0 / SCI1;                  选择端口;
    *               buf        the buffer;                       要发送的字符;
    *               length     the length of the buffer;        
    *               timeout    is the timeout (in clock ticks) to wait in case the buffer is full.  If you ...
    *                          ...specify a timeout of 0, the function will wait forever for the buffer to empty. 
    *                            在缓冲区满的情况下, 调用者最久愿意等待的时钟节拍数,为0表示永久等待.
    * Return:      SCI_NO_ERR        if the character was placed in the Tx buffer;  字符成功放入Tx缓冲区内;
    *              SCI_TX_TIMEOUT    if the buffer didn't empty or can't access within the specified timeout period;
    *                                    超时后还是没有清空缓冲区或者还无法访问
    *              SCI_BAD_CH        if you specify an invalid channel number  通道号错误
    *Note(s):      
    **********************************************************************************************
    */
    //INT8U SCI_PutStringB_Mutex(INT8U port, const INT8U *str, INT16U timeout){
        
      //   return SCI_PutCharsB_Mutex(port,str,strlen(str),timeout);
    //}
    
    /*
    *********************************************************************************************
    *                                        SCI_SendBuf_hold()
    *
    * Description : This function is called by your application to own the exclusive right of ...
    *                ...sending INT8U on particular SCI port. your function should look like this:
    *
    *                    SCI_SendBuf_hold(port,timeout,&err);
    *                    if (*err == SCI_NO_ERR){
    *                       .......
    *                        SCI_PutCharB(port,c,&err);
    *                       .......
    *                    }
    *                    SCI_SendBuf_release(port);
    *
    * Arguments : port      port can be SCI0/SCI1;                  选择端口;
    *             timeout   is the timeout (in clock ticks) to wait in case the buffer is occupied.  If you ...
    *                       ...specify a timeout of 0, the function will wait forever for the buffer to empty. 
    *                             在其他地方占有使用权的情况下, 调用者最久愿意等待的时钟节拍数,为0表示永久等待.
    *             perr      SCI_NO_ERR       if get the exclusive right of sending INT8U on particular SCI port successfully;  
    *                                            成功获取对应端口的发送权
    *                       SCI_TX_TIMEOUT   if can't get the exclusive right of sending INT8U on particular...
    *                                          ... SCI port within the specified timeout period;
    *                                            超时后还是没有获得对应端口的发送权
    *                       SCI_BAD_CH       if you specify an invalid channel number.  通道号错误
    *                       SCI_PEND_ISR     If you called this function from an ISR and the result would lead to a suspension.
    *                                            在ISR中调用了这个函数并且需要等待
    *                       SCI_PEND_LOCKED  If you called this function when the scheduler is locked.
    *                                            如果当系统调度器被锁住的时候调用的这个函数
    *                       SCI_ERR_UNKNOWN  
    * Note(s): 1. Don't use this function in ISR routine
    *             不要在ISR中使用这个函数
    *          2.Once call this function successfully, you must call SCI_SendBuf_release in the end of your function.  ...
    *               ... Otherwise, other caller to SCI_SendBuf_hold or SCI_XXX_Mutex mothod will fail.
    ********************************************************************************************
    */
    void  SCI_SendBuf_hold(INT8U port, INT16U timeout, INT8U *perr){
      portCheckTx4(SCI_BAD_CH);
      OSSemPend(pSCIBuf(port)->RingBufTxMutex,timeout,perr);        /* Wait for the right of use Tx buffer*/
      if(*perr == OS_ERR_NONE)
        *perr = SCI_NO_ERR;
      else if(*perr == OS_TIMEOUT)
        *perr = SCI_TX_TIMEOUT;                      /* Timed out, return error code             */  
      else if(*perr == OS_ERR_PEND_ISR)
        *perr = SCI_PEND_ISR;
      else if(*perr == OS_ERR_PEND_LOCKED)
        *perr = SCI_PEND_LOCKED;
      else 
        *perr = SCI_ERR_UNKNOWN;
    }
    /*
    *********************************************************************************************
    *                                        SCI_PutCharB()
    *
    * Description : This function is called by your application to send INT8U on the communications 
    *                  channel.  The function will wait for the buffer to empty out if the buffer is full. 
    *                  The function returns to your application if the buffer doesn't empty within the specified 
    *                  timeout.  A timeout value of 0 means that the calling function will wait forever for the 
    *                  buffer to empty out.  The character to send is first inserted into the Tx buffer and will 
    *                  be sent by the Tx ISR.  If this is the first character placed into the buffer, the Tx ISR 
    *                  will be enabled. 
    *
    * Arguments   : port     port can be SCI0 / SCI1;                  选择端口;
    *               c        the INT8U to send;                       要发送的字符;
    *               timeout  is the timeout (in clock ticks) to wait in case the buffer is full.  If you ...
    *                        ...specify a timeout of 0, the function will wait forever for the buffer to empty. 
    *                           在缓冲区满的情况下, 调用者最久愿意等待的时钟节拍数,为0表示永久等待.
    *
    * Return:       SCI_NO_ERR        if the character was placed in the Tx buffer;  
    *                                     字符成功放入Tx缓冲区内;
    *               SCI_TX_TIMEOUT    if the buffer didn't empty within the specified timeout period;
    *                                     超时后还是没有清空缓冲区
    *               SCI_BAD_CH        if you specify an invalid channel number  通道号错误
    *               SCI_PEND_ISR      If you called this function from an ISR and the result would lead to a suspension.
    *                                    在ISR中调用了这个函数并且需要等待
    *               SCI_PEND_LOCKED   If you called this function when the scheduler is locked.
    *                                    如果当系统调度器被锁住的时候调用的这个函数
    *               SCI_ERR_UNKNOWN  
    * Note(s): 1.  Don't use this function in ISR routine
    *               不要在ISR中使用这个函数
    *          2.  you should call SCI_SendBuf_hold() first unless you know what you are doing.
    *               调用这个函数前你应该先调用SCI_SendBuf_hold()，除非你知道你在干什么
    *********************************************************************************************
    */
    INT8U SCI_PutCharB (INT8U port, INT8U c, INT16U timeout){
      SCI_RING_BUF *pbuf;
      INT8U oserr;  
      portCheckTx2(SCI_BAD_CH);
      pbuf = pSCIBuf(port);
      oserr =  _SCI_TxPutCharB(pbuf,c,timeout);            /*  Put INT8U into Tx buffer*/ 
      if (oserr == OS_ERR_NONE)
        return (SCI_NO_ERR);  
      else if (oserr == OS_TIMEOUT)                        /* If Timeout happen */
        return (SCI_TX_TIMEOUT);                           /* Timed out, return error code   */  
      else if (oserr == OS_ERR_PEND_ISR) 
        return (SCI_PEND_ISR);
      else if (oserr == OS_ERR_PEND_LOCKED)
        return (SCI_PEND_LOCKED);
      else
        return (SCI_ERR_UNKNOWN);
    }
    /*
    *********************************************************************************************
    *                                        SCI_PutCharsB()
    *
    * Description : This function is called by your application to send INT8U on the communications 
    *                channel.  The function will wait for the buffer to empty out if the buffer is full. 
    *                The function returns to your application if the buffer doesn't empty within the specified 
    *                timeout.  A timeout value of 0 means that the calling function will wait forever for the 
    *                buffer to empty out.  The character to send is first inserted into the Tx buffer and will 
    *                be sent by the Tx ISR.  If this is the first character placed into the buffer, the Tx ISR 
    *                will be enabled. 
    *
    * Arguments   : port     port can be SCI0 / SCI1;         选择端口;
    *               buf      the buffer;                      要发送的缓冲区;
    *               length   the length of the buffer;        缓冲区长度;
    *               timeout  is the timeout (in clock ticks) to wait in case the buffer is full.  If you 
    *                          specify a timeout of 0, the function will wait forever for the buffer to empty. 
    *                         在缓冲区满的情况下, 调用者最久愿意等待的时钟节拍数,为0表示永久等待.
    *
    * Return:       SCI_NO_ERR      if the character was placed in the Tx buffer;  
    *                               字符成功放入Tx缓冲区内;
    *               SCI_TX_TIMEOUT  if the buffer didn't empty within the specified timeout period;
    *                               超时后还是没有清空缓冲区
    *               SCI_BAD_CH      if you specify an invalid channel number  通道号错误
    *               SCI_PEND_ISR    If you called this function from an ISR and the result would lead to a suspension.
    *                                    在ISR中调用了这个函数并且需要等待
    *               SCI_PEND_LOCKED If you called this function when the scheduler is locked.
    *                                    如果当系统调度器被锁住的时候调用的这个函数
    *               SCI_ERR_UNKNOWN  
    * Note(s): 1.  Don't use this function in ISR routine
    *               不要在ISR中使用这个函数
    *          2.  you should call SCI_SendBuf_hold() first unless you know what you are doing.
    *               调用这个函数前你应该先调用SCI_SendBuf_hold()，除非你知道你在干什么
    **********************************************************************************************
    */
    INT8U SCI_PutCharsB(INT8U port, const INT8U *buf,INT16U length, INT16U timeout) {
      SCI_RING_BUF *pbuf;  
      INT8U oserr;  
      portCheckTx2(SCI_BAD_CH);
      pbuf = pSCIBuf(port);
      while(length--){
        oserr =  _SCI_TxPutCharB(pbuf,*buf++,timeout);     /*  Put INT8U into Tx buffer*/ 
        if(oserr != OS_ERR_NONE)                           /* if any err happen */
          break;                                           /* break */ 
      }
      if (oserr == OS_ERR_NONE)
        return (SCI_NO_ERR);  
      else if (oserr == OS_TIMEOUT)                        /* If Timeout happen */
        return (SCI_TX_TIMEOUT);                           /* Timed out, return error code   */  
      else if (oserr == OS_ERR_PEND_ISR) 
        return (SCI_PEND_ISR);
      else if (oserr == OS_ERR_PEND_LOCKED)
        return (SCI_PEND_LOCKED);
      else
        return (SCI_ERR_UNKNOWN);
    }
    
    /*
    *********************************************************************************************
    *                                   SCI_SendBuf_release()
    *
    * Description :  This function is called by your application to release the exclusive right...
    *                 ... of sending INT8U on particular SCI port.
    *
    * Arguments   : port   port can be SCI0/SCI1;                  选择端口;
    *
    * Return:
    *
    *Note(s):        
    *********************************************************************************************
    */
    void  SCI_SendBuf_release(INT8U port){
      portCheckTx3();
      OSSemPost(pSCIBuf(port)->RingBufTxMutex);
    }
    
    /*
    **********************************************************************************************
    *                                        SCI_RxBufferIsEmpty()
    *
    * Description : To see if any character is available from the communications channel.  
    *                 查看是否接收缓冲区为空
    *
    * Arguments   : port     port can be SCI0 / SCI1;                  选择端口;
    *
    * Return      : If at least one character is available, the function returns FALSE(0) otherwise,...
    *                ... the function returns TRUE(1).
    *               0xff     if you specify an invalid channel number.
    *               如果缓冲区内存在字符，则返回FALSE，否则返回TRUE. 0xff 如果通道号无效.
    *Note(s):      
    **********************************************************************************************
    */
    INT8U  SCI_RxBufferIsEmpty (INT8U port)  
    {
    #if OS_CRITICAL_METHOD == 3u                           /* Allocate storage for CPU status register     */  
        OS_CPU_SR  cpu_sr = 0u;  
    #endif  
      INT8U empty;
      portCheckRx2(0xff);
      OS_ENTER_CRITICAL();  
      empty =  RingQueueIsEmpty(pSCIBuf(port)->RingBufRx);
      OS_EXIT_CRITICAL();  
      return (empty);
    }
    /*
    ********************************************************************************************
    *                                        SCI_TxBufferIsFull()
    *
    * Description: To see if any more characters can be placed in the Tx buffer.  
    *                  是否发送缓冲区已满
    *
    * Arguments  :  port    port can be SCI0 / SCI1;                  选择端口;
    *
    * Return     : If the buffer is full, the function returns TRUE. Otherwise, the function returns FALSE. 
    *              0xff                if you specify an invalid channel number.
    *              如果发送缓冲区满，则返回TRUE，否则返回FALSE. 0xff 如果通道号无效.
    *Note(s):      
    *********************************************************************************************
    */
    INT8U SCI_TxBufferIsFull (INT8U port)  
    {  
    #if OS_CRITICAL_METHOD == 3u                    /* Allocate storage for CPU status register     */  
        OS_CPU_SR  cpu_sr = 0u;  
    #endif  
        INT8U isfull;  
        SCI_RING_BUF *pbuf;  
        portCheckTx2(0xff);
        pbuf = pSCIBuf(port);
        OS_ENTER_CRITICAL();  
        isfull = RingQueueIsFull(pbuf->RingBufTx);
        OS_EXIT_CRITICAL();  
        return (isfull);  
    }  
    
    /*
    *********************************************************************************************************
    *                                LOCAL FUNCTION
    *********************************************************************************************************
    */
    #pragma CODE_SEG __NEAR_SEG NON_BANKED 
    // 内部用来放字符到发送缓冲区, 返回的是SemPend的错误，默认RingQueueIn是不可能出错的(因为有信号量保证有空间可用)
    static INT8U _SCI_TxPutCharB(pSCI_RING_BUF pbuf, INT8U c, INT16U timeout){
    #if OS_CRITICAL_METHOD == 3u                             /* Allocate storage for CPU status register */  
      OS_CPU_SR  cpu_sr = 0u;  
    #endif
      INT8U err,tmperr;
      OSSemPend(pbuf->RingBufTxSem, timeout, &err);        /* Wait for space in Tx buffer              */  
      if(err == OS_ERR_NONE){
        OS_ENTER_CRITICAL();
        /* Get next one from ring queue, and see whether this is the first character       */ 
        if (RingQueueIn(pbuf->RingBufTx,c,RQ_OPTION_WHEN_FULL_DISCARD_FIRST,&tmperr) == 1)  
          SCI_EnableTxInt(pbuf->port);                       /* Yes, Enable Tx interrupts                */  
        OS_EXIT_CRITICAL(); 
      }
      return err;
    }
    
    // This function is called by the Rx ISR to insert a character into the receive ring buffer.  
    // 这个函数由Rx ISR来插入一个字符到缓冲区内
    static void  _SCI_RxPutCharB (INT8U port, INT8U c)  
    {
         pSCI_RING_BUF pbuf;
         INT8U oserr;
         pbuf =  pSCIBuf(port);
         RingQueueIn(pbuf->RingBufRx,c,RQ_OPTION_WHEN_FULL_DISCARD_FIRST,&oserr);
         if(oserr == RQ_ERR_NONE)
            (void)OSSemPost(pbuf->RingBufRxSem);               /* Indicate that character was received     */  
    }
    // This function is called by the Tx ISR to extract the next character from the Tx buffer.  
    //    The perr will return SCI_TX_EMPTY if the buffer is empty.  This is done to signal the Tx ISR 
    //   to disable interrupts because there is no char to send.  
    // 这个函数由Tx ISR调用来从Tx缓冲区内提取下一个字符.如果发现没有字符可以提取了,perr就返回SCI_TX_EMPTY.
    //    这是用来通知Tx ISR禁止中断的。
    static INT8U _SCI_TxGetCharB (INT8U port, INT8U *perr)  
    {
        INT8U c;
        pSCI_RING_BUF pbuf;    
        pbuf =  pSCIBuf(port);
        c = RingQueueOut(pbuf->RingBufTx,perr);                   /* Get next one from ring queue.*/
        if(*perr == RQ_ERR_NONE){
           OSSemPost(pbuf->RingBufTxSem);
           *perr = SCI_NO_ERR;  
           return c;
        }else{
           *perr = SCI_TX_EMPTY;  
           return (FALSE);                                      /* Buffer is empty   */  
        }
    }
    
    static void SCI_ISR_Handler(INT8U port){
        INT8U status,err;
        volatile INT8U data; 
        status = SCISR1(port);
        if(status & 0x0F) // 0x1F = 0001 1111, if status is not Receive Data Reg Full Flag  
        {
            // See if we have some kind of error     
            // Clear interrupt (do nothing about it!) 
            data = SCIDRL(port);           // in case that compiler optimize this assignment,the 'data' must prefix volatile
        }
        else if(status & 0x20) //Receive Data Reg Full Flag  
        {
            _SCI_RxPutCharB(port, SCIDRL(port));                    // Insert received character into buffer       
        }
        else if(status & 0x80)  
        {
            data = _SCI_TxGetCharB(port, &err);             // Get next character to send.                 
            if (err == SCI_TX_EMPTY)   
            {                                            // Do we have anymore characters to send ?     
                                                         // No,  Disable Tx interrupts                  
                SCI_DisableTxInt(port);  
            }   
            else   
            {  
                SCIDRL(port) = data;        // Yes, Send character                  
            }                                             
        }
    }
    #pragma CODE_SEG DEFAULT
    void SCI0_ISR_Handler(void)  
    {
    #if(SCI0_UCOS_CODE_EN == TRUE)
       SCI_ISR_Handler(SCI0);
    #endif
    }
    
    void SCI1_ISR_Handler (void)  
    {
    #if(SCI1_UCOS_CODE_EN == TRUE)
       SCI_ISR_Handler(SCI1);
    #endif
    }
    
    void SCI2_ISR_Handler(void)  
    {
    #if(SCI2_UCOS_CODE_EN == TRUE)
        SCI_ISR_Handler(SCI2);
    #endif
    }
    
    void SCI3_ISR_Handler (void)  
    {  
    #if(SCI3_UCOS_CODE_EN == TRUE)
       SCI_ISR_Handler(SCI3);
    #endif
    } 
    
    void SCI4_ISR_Handler(void)  
    {  
    #if(SCI4_UCOS_CODE_EN == TRUE)
       SCI_ISR_Handler(SCI4);
    #endif
    }
    
    void SCI5_ISR_Handler (void)  
    {  
    #if(SCI5_UCOS_CODE_EN == TRUE)
       SCI_ISR_Handler(SCI5);
    #endif
    } 
    
    void SCI6_ISR_Handler(void)  
    {  
    #if(SCI6_UCOS_CODE_EN == TRUE)
       SCI_ISR_Handler(SCI6);
    #endif
    }
    
    void SCI7_ISR_Handler(void)
    {  
    #if(SCI7_UCOS_CODE_EN == TRUE)
       SCI_ISR_Handler(SCI7);
    #endif
    } 
    
    
    #endif  // of (SCI_MODULE_ENABLE == TRUE && SCI_UCOS_MODULE_ENABLE == TRUE)

头文件就不再发了，在[上一章][Link 1]中。

其中使用到了环形缓冲区，具体实现可以到我的[另一篇博文][Link 2]中找到。还使用了uCOS-II嵌入式操作系统提供的互斥型信号量以及信号量来保证不同任务对SCI口缓冲区的访问不发生冲突。每个SCI口都会对应一个接收以及一个发送缓冲区，对应的大小可以在.h文件中配置。

这个驱动的主要作用就是为每个SCI口提供缓冲区，一方面，SCI模块会不断的从发送缓冲区内获取字符并发送，另一方面，它会把接收到的字符不断放入接收缓冲区，这样所有经过SCI口的字节流都经过缓冲，有效缓解了处理不及时等现象。提供的函数也是围绕缓冲区的。

首先使用这个模块前一定要先调用SCI\_BufferInit函数来进行初始化。  
而由于一般来说一个SCI口只会有一个任务来接收SCI口的字节流，没有竞争的问题，所以只提供了SCI\_GetCharB函数来监听SCI口(和硬件驱动提供的SCI\_GetChar相比多了一个B，即Buffer)。一般来说会专门开个任务阻塞地监听这个信道，类似这样：

static  void  SCI0ListenTask (void *p_arg){
        INT8U c,err;
        ……
        while(true) {
            c = SCI_GetCharB(SCI0,RX_MAX_TIME_INTERVAL,&err); //从SCI0获得一个字符,最大等待RX_MAX_TIME_INTERVAL次TICK。
            if( err == SCI_RX_TIMEOUT ){          //超时导致的返回
                ……          // 超时的处理
                continue;
            }
            // 正常获得字符后的处理
            ……
        }
    }

而对于发送，因为有不同任务同时想用一个SCI口发送的问题，所以提供了互斥的方法，即SCI\_PutCharB\_Mutex和SCI\_PutCharsB\_Mutex，只要保证所有地方都使用这些互斥的方法发送，就可以保证不同任务间的发送互不干扰。  
比如：

任务一发送：abcde\r 
    任务二发送：12345\r

如果不使用互斥/独占的方法发送的话(比如直接调用硬件驱动提供的函数)，由于任务调度的原因，可能最后另外一头收到的就成了：abc12de\\r345\\r了。  
而如果使用互斥的方法的话，另一头就能保证收到的是 abcde\\r12345\\r  
另外，还提供的等价的互斥发送方法：SCI\_SendBuf\_hold、SCI\_PutCharB、SCI\_PutCharsB和SCI\_SendBuf\_release，他们需要成套使用，先用hold获取发送权，然后发送字节，最后释放发送权。这样就能保证在hold和release之间发送的字节的连续性了。

就讲到这里把，有什么建议或意见请留言。

--------------------

更改历史：

2017/10/29 更新到 V2.1 支持了所有的SCI口。  
2018/02/24 更新到 V2.2 例行优化

[http_blog.csdn.net_liyuanbhu_article_details_7764851]: http://blog.csdn.net/liyuanbhu/article/details/7764851
[Link 1]: http://blog.csdn.net/lin_strong/article/details/73521774
[Link 2]: http://blog.csdn.net/lin_strong/article/details/73604561