TI中文支持网下图是论坛上的一个帖子截图：
下面TMS320VC5509开发板中uart通信的MCBSP的配置程序：
/*—————————————————————————-*/
/* DESCRIPTION: */
/* */
/* This is an example for EMIF of C5509A */
/*—————————————————————————-*/
/* MODULE NAME… Mcbsp */
/* FILENAME…… uart.c */
/* DATE CREATED.. Mon 02/4/2004 */
/* COMPONENT….. */
/* PREREQUISITS.. */
/*—————————————————————————-*/
/* DESCRIPTION: */
/* */
/* this example is that the software uart is done by Mcbsp */
/*—————————————————————————-*/
#include <csl.h>
#include <csl_pll.h>
#include <csl_mcbsp.h>
#include <csl_irq.h>
#include <csl_timer.h>
#include <stdio.h>
//设置McBSP的PCR寄存器指针，用于读写其I/O端口
ioport unsigned int *PCR_1=(unsigned int *)0x2c12;
#define REG_PCR1 (*PCR_1)
/*锁相环的设置*/
PLL_Config myConfig = {
0, //IAI: the PLL locks using the same process that was underway
//before the idle mode was entered
1, //IOB: If the PLL indicates a break in the phase lock,
//it switches to its bypass mode and restarts the PLL phase-locking
//sequence
12, //PLL multiply value; multiply 12 times
0 //Divide by 1 PLL divide value; it can be either PLL divide value
//(when PLL is enabled), or Bypass-mode divide value
//(PLL in bypass mode, if PLL multiply value is set to 1)
};
/****************************设置Timer********************************/
/* 参考: TMS320VC5509 DSP Timers Reference Guide
TMS320C55x Chip Support Library API Reference Guide (Rev. J)
HX-5509A 开发板使用手册 */
//———Global data definition———//
#define TIMER_CTRL TIMER_TCR_RMK(\
TIMER_TCR_IDLEEN_DEFAULT, /* IDLEEN == 0 */ \
TIMER_TCR_FUNC_OF(0), /* FUNC == 0 */ \
TIMER_TCR_TLB_RESET, /* TLB == 1 */ \
TIMER_TCR_SOFT_BRKPTNOW, /* SOFT == 0 */ \
TIMER_TCR_FREE_WITHSOFT, /* FREE == 0 */ \
TIMER_TCR_PWID_OF(0), /* PWID == 0 */ \
TIMER_TCR_ARB_RESET, /* ARB == 1 */ \
TIMER_TCR_TSS_START, /* TSS == 0 */ \
TIMER_TCR_CP_PULSE, /* CP == 0 */ \
TIMER_TCR_POLAR_LOW, /* POLAR == 0 */ \
TIMER_TCR_DATOUT_0 /* DATOUT == 0 */ \
)
/* Create a TIMER configuration structure that can be passed */
/* to TIMER_config CSL function for initialization of Timer */
/* control registers. */
//产生1ms中断
TIMER_Config timCfg0 = {
TIMER_CTRL, /* TCR0 */
749, /* PRD0 */
0x0000 /* PRSC */
};
/* Create a TIMER_Handle object for use with TIMER_open */
TIMER_Handle mhTimer0;
Uint16 eventId0;
Uint16 timer0_cnt = 0;
int old_intm;
Uint16 tim_val;
//———Function prototypes———
/* Reference start of interrupt vector table */
/* This symbol is defined in file, vectors_timer1.s55 */
extern void VECSTART(void);
/* Function/ISR prototypes */
interrupt void timer0Isr(void);
/***********************************************************************/
/**************************McBSP1设置成GPIO*****************************/
/* 参考: TMS320C55x DSP Multichannel Buffered Serial Port (McBSP) Reference Guide
HX-5509A 开发板使用手册
TMS320C55x Chip Support Library API Reference Guide (Rev. J) */
MCBSP_Config Mcbsptest;
MCBSP_Config Mcbsp1Config = {
MCBSP_SPCR1_RMK(
MCBSP_SPCR1_DLB_OFF, /* DLB = 0,禁止自闭环方式 */
MCBSP_SPCR1_RJUST_LZF, /* RJUST = 2 */
MCBSP_SPCR1_CLKSTP_DISABLE, /* CLKSTP = 0 */
MCBSP_SPCR1_DXENA_ON, /* DXENA = 1 */
0, /* ABIS = 0 */
MCBSP_SPCR1_RINTM_RRDY, /* RINTM = 0 */
0, /* RSYNCER = 0 */
MCBSP_SPCR1_RRST_DISABLE /* RRST = 0 */
),
MCBSP_SPCR2_RMK(
MCBSP_SPCR2_FREE_NO, /* FREE = 0 */
MCBSP_SPCR2_SOFT_NO, /* SOFT = 0 */
MCBSP_SPCR2_FRST_FSG, /* FRST = 0 */
MCBSP_SPCR2_GRST_CLKG, /* GRST = 0 */
MCBSP_SPCR2_XINTM_XRDY, /* XINTM = 0 */
0, /* XSYNCER = N/A */
MCBSP_SPCR2_XRST_DISABLE /* XRST = 0 */
),
/*单数据相，接受数据长度为16位,每相2个数据*/
MCBSP_RCR1_RMK(
MCBSP_RCR1_RFRLEN1_OF(1), /* RFRLEN1 = 1 */
MCBSP_RCR1_RWDLEN1_16BIT /* RWDLEN1 = 2 */
),
MCBSP_RCR2_RMK(
MCBSP_RCR2_RPHASE_SINGLE, /* RPHASE = 0 */
MCBSP_RCR2_RFRLEN2_OF(0), /* RFRLEN2 = 0 */
MCBSP_RCR2_RWDLEN2_8BIT, /* RWDLEN2 = 0 */
MCBSP_RCR2_RCOMPAND_MSB, /* RCOMPAND = 0 */
MCBSP_RCR2_RFIG_YES, /* RFIG = 0 */
MCBSP_RCR2_RDATDLY_1BIT /* RDATDLY = 1 */
),
MCBSP_XCR1_RMK(
MCBSP_XCR1_XFRLEN1_OF(1), /* XFRLEN1 = 1 */
MCBSP_XCR1_XWDLEN1_16BIT /* XWDLEN1 = 2 */
),
MCBSP_XCR2_RMK(
MCBSP_XCR2_XPHASE_SINGLE, /* XPHASE = 0 */
MCBSP_XCR2_XFRLEN2_OF(0), /* XFRLEN2 = 0 */
MCBSP_XCR2_XWDLEN2_8BIT, /* XWDLEN2 = 0 */
MCBSP_XCR2_XCOMPAND_MSB, /* XCOMPAND = 0 */
MCBSP_XCR2_XFIG_YES, /* XFIG = 0 */
MCBSP_XCR2_XDATDLY_1BIT /* XDATDLY = 1 */
),
MCBSP_SRGR1_DEFAULT,
MCBSP_SRGR2_DEFAULT,
MCBSP_MCR1_DEFAULT,
MCBSP_MCR2_DEFAULT,
MCBSP_PCR_RMK(
MCBSP_PCR_IDLEEN_RESET, /* IDLEEN = 0 */
MCBSP_PCR_XIOEN_GPIO, /* XIOEN = 1 */
MCBSP_PCR_RIOEN_GPIO, /* RIOEN = 1 */
MCBSP_PCR_FSXM_EXTERNAL, /* FSXM = 0 */
MCBSP_PCR_FSRM_EXTERNAL, /* FSRM = 0 */
MCBSP_PCR_CLKXM_INPUT, /* CLKXM = 0 */
MCBSP_PCR_CLKRM_INPUT, /* CLKRM = 0 */
MCBSP_PCR_SCLKME_NO, /* SCLKME = 0 */
MCBSP_PCR_DXSTAT_1, /* DXSTAT = 1 */
MCBSP_PCR_FSXP_ACTIVEHIGH, /* FSXP = 0 */
MCBSP_PCR_FSRP_ACTIVEHIGH, /* FSRP = 1 */
MCBSP_PCR_CLKXP_FALLING, /* CLKXP = 1 */
MCBSP_PCR_CLKRP_RISING /* CLKRP = 1 */
),
MCBSP_RCERA_DEFAULT,
MCBSP_RCERB_DEFAULT,
MCBSP_RCERC_DEFAULT,
MCBSP_RCERD_DEFAULT,
MCBSP_RCERE_DEFAULT,
MCBSP_RCERF_DEFAULT,
MCBSP_RCERG_DEFAULT,
MCBSP_RCERH_DEFAULT,
MCBSP_XCERA_DEFAULT,
MCBSP_XCERB_DEFAULT,
MCBSP_XCERC_DEFAULT,
MCBSP_XCERD_DEFAULT,
MCBSP_XCERE_DEFAULT,
MCBSP_XCERF_DEFAULT,
MCBSP_XCERG_DEFAULT,
MCBSP_XCERH_DEFAULT
};
MCBSP_Handle hMcbsp;
/***********************************************************************/
Uint16 i,temp;
unsigned char timer0_cnten;
unsigned char uart_rec, uart_send, uart_recflag, uart_sendflag;
unsigned char uart_bitscan, uart_bitcnt, uart_recstart, uart_sendbitcnt;
unsigned char uart_bitsend, uart_bitsendcnt, uart_sendcnten, uart_sendend;
void delay(Uint32 k)
{
while(k–);
}
void settimer(void)
{
/* Set IVPH/IVPD to start of interrupt vector table */
/*修改寄存器IVPH，IVPD，重新定义中断向量表*/
IRQ_setVecs((Uint32)(&VECSTART));
/* Temporarily disable all maskable interrupts */
old_intm = IRQ_globalDisable();
/* Open Timer 0, set registers to power on defaults */
mhTimer0 = TIMER_open(TIMER_DEV0, TIMER_OPEN_RESET);
/* Get Event Id associated with Timer 0, for use with */
/* CSL interrupt enable functions. */
eventId0 = TIMER_getEventId(mhTimer0);
/* Clear any pending Timer interrupts */
IRQ_clear(eventId0);
/* Place interrupt service routine address at */
/* associated vector location */
IRQ_plug(eventId0,&timer0Isr);
/* Write configuration structure values to Timer control regs */
TIMER_config(mhTimer0, &timCfg0);
/* Enable Timer interrupt */
IRQ_enable(eventId0);
/* Enable all maskable interrupts */
IRQ_globalEnable();
timer0_cnten = 0;
uart_bitscan = 0;
uart_bitcnt = 0;
uart_recstart = 0;
uart_recflag = 0;
uart_sendflag = 0;
/* Start Timer */
TIMER_start(mhTimer0);
}
void main(void)
{
/* Initialize CSL library – This is REQUIRED !!! */
/*初始化CSL库*/
CSL_init();
/*设置系统的运行速度为144MHz*/
PLL_config(&myConfig);
/*初始化McBSP1*/
hMcbsp = MCBSP_open(MCBSP_PORT1,MCBSP_OPEN_RESET);
/*设置McBSP1*/
MCBSP_config(hMcbsp,&Mcbsp1Config);
MCBSP_getConfig(hMcbsp,&Mcbsptest);
settimer();
/*************************以下程序实现软件Uart************************/
/* 参考：HX-5509A 开发板使用手册 */
while(TRUE)
{
if(uart_recflag==1)
{
uart_recflag = 0;
if(uart_sendflag==0)
{
uart_bitsendcnt = 0;
uart_sendend = 0;
uart_sendcnten = 0;
uart_bitsend = 0;
uart_send = uart_rec;
uart_sendflag = 1;
uart_sendbitcnt = 0;
}
}
};
}
interrupt void timer0Isr(void)
{
temp = REG_PCR1;
//Send
if(uart_sendflag==1)
{
if(uart_sendcnten==0)
{
REG_PCR1 &= 0xffdf;
uart_bitsend = 1;
uart_sendcnten = 1;
}
if(uart_sendcnten==1)
{
uart_bitsendcnt++;
if(uart_bitsendcnt==10)
{
uart_sendbitcnt++;
if(uart_sendend==1)
{
uart_sendflag = 0;
}
else
{
if(uart_sendbitcnt<9)
{
if((uart_send & uart_bitsend)==0)
{
REG_PCR1 &= 0xffdf;
}
else
{
REG_PCR1 |= 0x0020;
}
uart_bitsend <<= 1;
}
else
{
REG_PCR1 |= 0x0020;
uart_sendflag = 0;
}
}
uart_bitsendcnt = 0;
}
}
}
//Receive
if((uart_bitcnt==0)&&(uart_recstart==0))
{
if((temp&0x0010)==0)
{
timer0_cnt = 0;
timer0_cnten = 1;
uart_bitscan = 0;
uart_rec = 0;
uart_recstart = 1;
}
}
if(timer0_cnten==1)
{
timer0_cnt++;
if((temp&0x0010)!=0)
{
uart_bitscan++;
}
if(timer0_cnt==10)
{
timer0_cnt = 0;
if(uart_bitscan>5)
{
switch(uart_bitcnt)
{
case 0: uart_rec = 0;
timer0_cnten = 0;
uart_recstart = 0;
break;
case 1: uart_bitcnt++;
uart_rec |= 0x01;
break;
case 2: uart_bitcnt++;
uart_rec |= 0x02;
break;
case 3: uart_bitcnt++;
uart_rec |= 0x04;
break;
case 4: uart_bitcnt++;
uart_rec |= 0x08;
break;
case 5: uart_bitcnt++;
uart_rec |= 0x10;
break;
case 6: uart_bitcnt++;
uart_rec |= 0x20;
break;
case 7: uart_bitcnt++;
uart_rec |= 0x40;
break;
case 8: uart_bitcnt++;
uart_rec |= 0x80;
break;
case 9: uart_bitcnt = 0;
timer0_cnten = 0;
uart_recflag = 1;
uart_recstart = 0;
break;
default: break;
}
}
else
{
uart_bitcnt++;
if(uart_bitcnt>9)
{
uart_bitcnt = 0;
timer0_cnten = 0;
}
}
uart_bitscan = 0;
}
}
}
/******************************************************************************\
* End of uart.c
\******************************************************************************/
按照帖子中公式计算的话，在这个程序中，CPU Clock frequency的值应该是144MHz，DSP端通过timer设置为192 000，采用10倍过采样，band rate=19200，这样的话计算出来的结果CKLGDV=468大于255，且与配置的MCBSP_SRGR1_DEFAULT运行之后，SRGR1结果为0x0001，这是为什么？
Tony Tang：
现在很多新的芯片，如C5515，C5535, C5517等都还有硬件的UART，而且性价比也更高，不防选择新的器件来做设计吧。
