C AT91sam7x 256:中断仅运行一次
我在at91sam7x256上使用带DMA的USART读取和写入数据。 由于我没有成功,我开始创建一个简单的示例,但问题已经存在。 主要问题是中断程序第一次启动,第一次启动后我无法从USART接收数据C AT91sam7x 256:中断仅运行一次,c,arm,embedded,interrupt,keil,C,Arm,Embedded,Interrupt,Keil,我在at91sam7x256上使用带DMA的USART读取和写入数据。 由于我没有成功,我开始创建一个简单的示例,但问题已经存在。 主要问题是中断程序第一次启动,第一次启动后我无法从USART接收数据 #include "at91sam7x256.h" char Buffer[10]; // holds received characters unsigned long nChars = 0; // counts num
#include "at91sam7x256.h"
char Buffer[10]; // holds received characters
unsigned long nChars = 0; // counts number of received chars
char *pBuffer = &Buffer[0]; // pointer into Buffer
void Usart0IrqHandler (void);
void USART0Setup(void);
int main(void)
{
unsigned long j;
unsigned int IdleCount = 0;
// set up USART0
USART0Setup();
// *****************************
// * endless blink loop *
// *****************************
while (1) {
for (j = 1000000; j != 0; j-- ); // wait 1 second 1000000
IdleCount++; // count # of times through the idle loop
for (j = 1000000; j != 0; j-- ); // wait 1 second 1000000
}
}
////////
void Usart0IrqHandler (void) {
volatile AT91PS_USART pUsart0 = AT91C_BASE_US0; // create a pointer to USART0 structure
if ((pUsart0->US_CSR & AT91C_US_ENDRX) == AT91C_US_ENDRX) {
// we have a end-of-receive interrupt (ENDRX)
pUsart0->US_RCR = 10; // restore the receive count - clears ENDRX flag
}
}
void USART0Setup(void) {
volatile AT91PS_USART pUSART0 = AT91C_BASE_US0; // create a pointer to USART0 structure
volatile AT91PS_AIC pAIC = AT91C_BASE_AIC; // pointer to AIC data structure
volatile AT91PS_PIO pPIO = AT91C_BASE_PIOA; // pointer to PIO data structure
volatile AT91PS_PMC pPMC = AT91C_BASE_PMC; // pointer to PMC data structure
pPMC->PMC_PCER = (1<<AT91C_ID_US0); // enable usart0 peripheral clock
pPIO->PIO_PDR = AT91C_PA0_RXD0 | AT91C_PA1_TXD0; // enable peripheral control of PA0 and PA1 (RXD0 and TXD0)
pPIO->PIO_ASR = AT91C_PIO_PA0 | AT91C_PIO_PA1; // assigns the 2 I/O lines to peripheral A function
pPIO->PIO_BSR = 0; // peripheral B function set to "no effect"
pUSART0->US_CR = AT91C_US_RSTRX | // reset receiver
AT91C_US_RSTTX | // reset transmitter
AT91C_US_RXDIS | // disable receiver
AT91C_US_TXDIS; // disable transmitter
pUSART0->US_MR = AT91C_US_PAR_NONE | // no parity
0x3 << 6; // 8-bit characters
pUSART0->US_IER = 0x00; // no usart0 interrupts enabled (no effect)
pUSART0->US_IDR = 0xFFFF; // disable all USART0 interrupts
pUSART0->US_BRGR = 0x139; // CD = 0x139 (313 from above calculation for 9600 baud)
// FP=0 (not used)
pUSART0->US_RTOR = 0; // receiver time-out (disabled)
pUSART0->US_TTGR = 0; // transmitter timeguard (disabled)
pUSART0->US_RPR = (unsigned int)Buffer; // address of DMA input buffer
pUSART0->US_RCR = 10; // we'll read in 10 chars via DMA
pUSART0->US_TPR = (unsigned int)0; // address of DMA output buffer (use same one)
pUSART0->US_TCR = 0; // we'll transmit 0 chars via DMA
pUSART0->US_RNPR = (unsigned int)0; // next DMA receive buffer address
// if set to zero, it is not used
pUSART0->US_RNCR = (unsigned int)0; // next DMA receive counter
// if set to zero, it is not used
pUSART0->US_TNPR = (unsigned int)0; // next DMA transmit buffer address
// if set to zero, it is not used
pUSART0->US_TNCR = (unsigned int)0; // next DMA transmit counter
// if set to zero, it is not used
pUSART0->US_PTCR = AT91C_PDC_RXTEN | // enable receive transfer,
AT91C_PDC_TXTDIS; // disable transmit transfer
// Disable USART0 interrupt in AIC Interrupt Disable Command Register
pAIC->AIC_IDCR = (1<<AT91C_ID_US0);
// Set the USART0 IRQ handler address in AIC Source
pAIC->AIC_SVR[AT91C_ID_US0] =
(unsigned int)Usart0IrqHandler; // Vector Register[6]
// Set the interrupt source type and priority
pAIC->AIC_SMR[AT91C_ID_US0] =
(AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL | 0x4 ); // in AIC Source Mode Register[6]
// Enable the USART0 interrupt in AIC Interrupt Enable Command Register
pAIC->AIC_IECR = (1<<AT91C_ID_US0);
// enable the USART0 receiver and transmitter
pUSART0->US_CR = AT91C_US_RXEN | AT91C_US_TXEN;
// enable the USART0 end-of-receive interrupt
pUSART0->US_IER = AT91C_US_ENDRX; // enable ENDRX usart0 end-of-receive interrupt
pUSART0->US_IDR = ~AT91C_US_ENDRX; // disable all interrupts except ENDRX
}
//------------------
// end of file
//------------------
#包括“at91sam7x256.h”
字符缓冲区[10];//保存接收到的字符
无符号长nChars=0;//统计收到的字符数
char*pBuffer=&Buffer[0];//指向缓冲区的指针
无效Usart0IrqHandler(无效);
作废USART0Setup(作废);
内部主(空)
{
无符号长j;
无符号整数IdleCount=0;
//设置USART0
USART0Setup();
// *****************************
//*无休止的闪烁循环*
// *****************************
而(1){
对于(j=1000000;j!=0;j--);//等待1秒1000000
IdleCount++;//通过idle循环的次数
对于(j=1000000;j!=0;j--);//等待1秒1000000
}
}
////////
void Usart0IrqHandler(void){
volatile AT91PS_USART pUsart0=AT91C_BASE_US0;//创建指向USART0结构的指针
如果((pUsart0->US_CSR&AT91C_US_ENDRX)==AT91C_US ENDRX){
//我们有一个接收端中断(ENDRX)
pUsart0->US_RCR=10;//恢复接收计数-清除ENDRX标志
}
}
作废USART0Setup(作废){
volatile AT91PS_USART pUSART0=AT91C_BASE_US0;//创建指向USART0结构的指针
volatile AT91PS_AIC pAIC=AT91C_BASE_AIC;//指向AIC数据结构的指针
volatile AT91PS_PIO pPIO=AT91C_BASE_PIOA;//指向PIO数据结构的指针
易失性AT91PS_PMC pPMC=AT91C_BASE_PMC;//指向PMC数据结构的指针
pPMC->PMC_PCER=(1PIO_ASR=AT91C_PIO_PA0 | AT91C_PIO_PA1;//将两条I/O线分配给外设功能
pPIO->PIO_BSR=0;//外围B功能设置为“无效”
pUSART0->US_CR=AT91C_US_RSTRX |//重置接收机
AT91C_US_RSTTX |//重置变送器
AT91C_US_RXDIS |//禁用接收器
AT91C_US_TXDIS;//禁用变送器
pUSART0->US_MR=AT91C_US_PAR_NONE |//无奇偶校验
0x3 US_IER=0x00;//未启用usart0中断(无效果)
pUSART0->US_IDR=0xFFFF;//禁用所有USART0中断
pUSART0->US_BRGR=0x139;//CD=0x139(根据上述9600波特的313计算)
//FP=0(未使用)
pUSART0->US\u RTOR=0;//接收器超时(禁用)
pUSART0->US_TTGR=0;//变送器时间保护(禁用)
pUSART0->US_RPR=(unsigned int)Buffer;//DMA输入缓冲区的地址
pUSART0->US_RCR=10;//我们将通过DMA读取10个字符
pUSART0->US_TPR=(unsigned int)0;//DMA输出缓冲区的地址(使用相同的地址)
pUSART0->US_TCR=0;//我们将通过DMA传输0个字符
pUSART0->US_RNPR=(unsigned int)0;//下一个DMA接收缓冲区地址
//如果设置为零,则不使用
pUSART0->US_RNCR=(unsigned int)0;//下一个DMA接收计数器
//如果设置为零,则不使用
pUSART0->US_TNPR=(unsigned int)0;//下一个DMA传输缓冲区地址
//如果设置为零,则不使用
pUSART0->US_TNCR=(unsigned int)0;//下一个DMA传输计数器
//如果设置为零,则不使用
pUSART0->US_PTCR=AT91C_PDC_RXTEN |//启用接收传输,
AT91C_PDC_TXTDIS;//禁用传输
//在AIC中断禁用命令寄存器中禁用USART0中断
pAIC->AIC_IDCR=(1AIC_SMR[AT91C_ID_US0]=
(AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL | 0x4);//在AIC源模式寄存器中[6]
//在AIC中断启用命令寄存器中启用USART0中断
pAIC->AIC_IECR=(1US_IER=AT91C_US_ENDRX;//启用ENDRX usart0接收中断结束
pUSART0->US_IDR=~AT91C_US_ENDRX;//禁用除ENDRX之外的所有中断
}
//------------------
//文件结束
//------------------
在设置中断中的计数(US\u RCR)之前,您需要重新初始化接收指针:
pUSART0->US_RPR = (unsigned int)Buffer;
您的设备可能出现故障,因为PDC正在缓冲区外写入数据。有两个问题:1-当我使用Keil uVision时,我需要使用
\uu irq
来定义中断服务例程!2-令人惊讶的是,中断结束时没有触发!因此使用:
*AT91C\U AIC\U EOICR=0;
void __irq Usart0IrqHandler (void) {
volatile AT91PS_USART pUsart0 = AT91C_BASE_US0; // create a pointer to USART0 structure
if ((pUsart0->US_CSR & AT91C_US_ENDRX) == AT91C_US_ENDRX) {
pUsart0->US_RPR = (unsigned int)Buffer; // we have a end-of-receive interrupt (ENDRX)
pUsart0->US_RCR = 10; // restore the receive count - clears ENDRX flag
}
*AT91C_AIC_EOICR = 0; // end of interrupts
}
标准警告;使用
stdint.h
固定宽度类型而不是标准类型。Ooops:)我忘记重置缓冲区,但这与问题无关。我找到了原因并将其作为答案发布