我用的是at91sam7x256芯片，怎么调串口也调不通，不知道哪里出问题了。不过要是把以前我写的一个可以正常运行的程序（包括串口驱动）下载到板子上以后就可以正常运行了，如果把板子清空，就又不能运行了，可能是初始化时错了，但又找不出来，大家帮帮啊，谢谢了啊。
源代码如下：
#include "/include/at91sam7S64/at91sam7s64.h"
#include "/include/at91sam7s64/lib_at91sam7s64.h"
void AT91F_LowLevelInit(void);
void usart0_init(void);
void usart0_write(char * tx_buffer, unsigned int tx_counter);
#define MCLK 48000000
#define BAUD 19200
int CMain(void)
{
int index = 500000;
AT91F_LowLevelInit();
usart0_init();
while(1)
{
usart0_write("Hello, World!
", 14);
while(index--);
index = 500000;
}
return 0;
}
void AT91F_LowLevelInit(void)
{
//Disables the Watchdog Timer
AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;
//Enabling the Main Oscillator
AT91C_BASE_PMC->PMC_MOR = 0x01 | 0x07 << 8;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS))
//Setting PLL and divider
AT91C_BASE_PMC->PMC_PLLR = 24 | (0x28 << 8) | (124 << 16) | AT91C_CKGR_USBDIV_1;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCK));
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
//Selection of Processor Clock
AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_PRES_CLK_2;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
//Selection of Master Clock
AT91C_BASE_PMC->PMC_MCKR |= AT91C_PMC_CSS_PLL_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
}
void usart0_init(void)
{
AT91F_US0_CfgPMC();
AT91F_US0_CfgPIO();
AT91F_US_Configure(
AT91C_BASE_US0,
MCLK,
AT91C_US_ASYNC_MODE,
BAUD,
0);
AT91C_BASE_US0->US_CR = AT91C_US_RXEN | AT91C_US_TXEN | AT91C_US_STTTO;
}
void usart0_write(char * tx_buffer, unsigned int tx_counter)
{
AT91C_BASE_PDC_US0->PDC_TPR = (unsigned int)tx_buffer;
AT91C_BASE_PDC_US0->PDC_TCR = tx_counter;
AT91F_PDC_EnableTx (AT91C_BASE_PDC_US0);
//while (AT91C_BASE_PDC_US0->PDC_TCR & 0xFFFF);
}
|
楼主
标题置顶
标题高亮
