[资料分享] DSP28335使用FIFO的串口中断总结

实现一个功能的时候首先查看相关的资料，例如数据手册，论坛、百度、书籍等，搜集各种相关资料，然后看别人是如何实现的，分析下相关步骤，理清好思路。针对不懂的地方继续查找资料，层层递进。（如果想省事，可以在别人正确代码的基础上进行修改，看他配置了什么寄存器，实现了什么功能，然后根据自己的需求，查看数据手册重新配置），实现的时候可以一个个小功能的实现，遇到疑惑的除求助外，也可试着观察不同的情况下会出现什么结果。总之就是多搜，多想，多动手，多总结。

#include "DSP2833x_Device.h"
#include "DSP2833x_Examples.h"
#define SCIB 0
#define SCIC 1
// Prototype statements for functions found within this file.
void scic_fifo_init(void);
void scic_xmit(int a);
interrupt void uart_send(void);
 
// Global counts used in this example
Uint16 isrCount=0;
Uint16 ErrorCount=0;
Uint16 sdata[4]={5,5,5,5};//要发送的数据
void main(void)
{
    Uint16 i=0;
// Step 1. Initialize System Control registers, PLL, WatchDog, Clocks to default state:
// This function is found in the DSP2833x_SysCtrl.c file.
    InitSysCtrl();
 
// Step 2. Select GPIO for the device or for the specific application:
// This function is found in the DSP2833x_Gpio.c file.
// InitGpio(); skip this as this is example selects the I/O
// for SCI-A in this file itself
   InitSciGpio();
 
// Step 3. Initialize PIE vector table:
// The PIE vector table is initialized with pointers to shell Interrupt
// Service Routines (ISR).  The shell routines are found in DSP2833x_DefaultIsr.c.
// Insert user specific ISR code in the appropriate shell ISR routine in
// the DSP28_DefaultIsr.c file.
 
// Disable and clear all CPU interrupts:
    DINT;
    IER = 0x0000;
    IFR = 0x0000;
 
      // Initialize Pie Control Registers To Default State:
      // This function is found in the DSP2833x_PieCtrl.c file.
      // InitPieCtrl();  PIE is not used for this example
 
      // Initialize the PIE Vector Table To a Known State:
      // This function is found in DSP2833x_PieVect.c.
      // This function populates the PIE vector table with pointers
      // to the shell ISR functions found in DSP2833x_DefaultIsr.c.
      InitPieVectTable();
 
      // Enable CPU and PIE interrupts
      // This example function is found in the DSP2833x_PieCtrl.c file.
      EnableInterrupts();
 
// Step 4. Initialize all the Device Peripherals to a known state:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); skip this for SCI tests
// Step 5. User specific functions, Reassign vectors (optional), Enable Interrupts:
 
    isrCount = 0;
    ErrorCount = 0;
#if SCIB
    scib_fifo_init();       // Initialize the SCI FIFO
    scib_loopback_init();  // Initalize SCI
#elif SCIC
    scic_fifo_init();       // Initialize the SCI FIFO
#endif
// Send a character ,先给发送缓冲寄存器赋值。
    for(i=0;i<4;i++)
    {
        scic_xmit(sdata[i]+0x30);
    }
   scic_xmit(' ');
// Step 6. Send Characters forever starting with 0x00 and going through
// 0xFF.  After sending each, check the recieve buffer for the correct value
 EALLOW;  
//  PieVectTable.SCIRXINTC = &uartIsr;  
    PieVectTable.SCITXINTC = &uart_send;  
    EDIS;  
    PieCtrlRegs.PIECTRL.bit.ENPIE=1;  
//  PieCtrlRegs.PIEIER8.bit.INTx5=1;  
    PieCtrlRegs.PIEIER8.bit.INTx6=1;  
    IER|=M_INT8;  
    EINT;  
    ERTM;    
    for(;;){ }
}
interrupt void uart_send(void)  
{  
    Uint16 i;   
    isrCount++;
    sdata[3]=isrCount;
    for(i=0;i<4;i++)
    {
      scic_xmit(sdata[i]+0x30);
    }  
    scic_xmit(' ');
    if(isrCount==10)
    {
        ScicRegs.SCICTL1.bit.TXENA =0;//禁止发送缓冲器工作。
    }
    PieCtrlRegs.PIEACK.all=0xffff;//0x0080;
    ScicRegs.SCIFFTX.bit.TXFFINTCLR=1;    // Clear SCI Interrupt flag
}  
 
// Transmit a character from the SCI'
void scic_xmit(int a)//发送一个数据a，类型为int
{
   ScicRegs.SCITXBUF=a;//向数据缓冲寄存器中写入数据即可发送该数据
}
 
// Initalize the SCI FIFO
void scic_fifo_init()
{
// Test 1,SCIC  DLB, 8-bit word, baud rate 9.6k, default, 1 STOP bit, no parity
//功能是配置发送模式
// Note: Clocks were turned on to the SCIC peripheral
//  in the InitSysCtrl() function
//  ScicRegs.SCICTL1.all =0x0000; //开始的时候先禁止接收与发送功能
    ScicRegs.SCICCR.all =0x0007;   // 1 stop bit,  No loopback
                                   // No parity,8 char bits,                   
                                   // async mode, idle-line protocol
//数据长度8位，一个结束位，无奇偶校验，空闲线模式，禁止回送    
                                 
//  ScicRegs.SCICTL1.all =0x0003;  // enable TX, RX, internal SCICLK,
                                      // Disable RX ERR, SLEEP, TXWAKE
                                   
    ScicRegs.SCICTL1.all =0x0002; //允许发送，禁止接收                              
//  ScicRegs.SCICTL2.all =0x0001;//发送缓冲器中断使能。似乎与下面的重复了
    ScicRegs.SCICTL2.bit.TXINTENA =1;//发送缓冲器中断使能。
//  ScicRegs.SCICTL2.bit.RXBKINTENA =1;
    ScicRegs.SCIHBAUD    =0x0001;
    ScicRegs.SCILBAUD    =0x00e7;
 //上面是波特率设置，书上写的0x00e7   
    
//  ScicRegs.SCICCR.bit.LOOPBKENA =0;// enable(Disable) loop back
    ScicRegs.SCICTL1.all =0x0022;     // Relinquish SCI from Reset
//FIFO设置
    ScicRegs.SCIFFTX.bit.TXFIFOXRESET=0;
//  ScicRegs.SCIFFRX.bit.RXFIFORESET=0;
 
    ScicRegs.SCIFFTX.all=0xE060;
//  ScicRegs.SCIFFRX.all=0x204f;
    ScicRegs.SCIFFCT.all=0x0;
}
 
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// No more.
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