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器件型号：TMS320F28374S 工具与软件：
CCS 版本：12.6.0
编译版本：TI v22.6.0.1.TLS
芯片模型：TMS320F28374S
GPIO 初始化代码如下：
void scib_gpio54_55_init(void)
{
EALLOW;
const uint16_t mux54 = 6; // GPIO54_MUX = 6: SCIB_TX
const uint16_t mux55 = 6; // GPIO55_MUX = 6: SCIB_RX
GpioCtrlRegs.GPBGMUX2.bit.GPIO54 = mux54 / 4;
GpioCtrlRegs.GPBMUX2.bit.GPIO54 = mux54 % 4;
GpioCtrlRegs.GPBPUD.bit.GPIO54 = 0; // 0: enable pull up
GpioCtrlRegs.GPBDIR.bit.GPIO54 = 1; // 0:input 1:output
GpioCtrlRegs.GPBGMUX2.bit.GPIO55 = mux55 / 4;
GpioCtrlRegs.GPBMUX2.bit.GPIO55 = mux55 % 4;
GpioCtrlRegs.GPBPUD.bit.GPIO55 = 0; // 0: enable pull up
GpioCtrlRegs.GPBDIR.bit.GPIO55 = 0; // 0:input 1:output
EDIS;
}
void scia_gpio35_36_init(void)
{
EALLOW;
const uint16_t mux35 = 1; // GPIO35_MUX = 1: SCIA_RX
const uint16_t mux36 = 1; // GPIO36_MUX = 1: SCIA_TX
// SCIA_RX
GpioCtrlRegs.GPBGMUX1.bit.GPIO35 = mux35 / 4; // 0:GPIO 1:RXD
GpioCtrlRegs.GPBMUX1.bit.GPIO35 = mux35 % 4; // 0:GPIO 1:RXD
GpioCtrlRegs.GPBPUD.bit.GPIO35 = 0; // enable pull up
GpioCtrlRegs.GPBDIR.bit.GPIO35 = 0; // 0:input 1:output
// SCIA_TX
GpioCtrlRegs.GPBGMUX1.bit.GPIO36 = mux36 / 4; // 0:GPIO 1:TXD
GpioCtrlRegs.GPBMUX1.bit.GPIO36 = mux36 % 4; // 0:GPIO 1:TXD
GpioCtrlRegs.GPBPUD.bit.GPIO36 = 0; // enable pull up
GpioCtrlRegs.GPBDIR.bit.GPIO36 = 1; // 0:input 1:output
EDIS;
}SCI 初始化代码如下：
void scib_init(uint32_t baud_rate)
{
uint16_t prescale = (uint16_t)(get_clock_freq() / 4 / baud_rate / 8 - 1);
ScibRegs.SCICTL1.all = 0x00; // reset SCI
ScibRegs.SCICCR.all = 0x07; // 1 bit stop, disable parity, idle mode, 8 bits data
ScibRegs.SCIHBAUD.bit.BAUD = prescale / 256;
ScibRegs.SCILBAUD.bit.BAUD = prescale % 256;
ScibRegs.SCIFFRX.bit.RXFIFORESET = 1; // 1:enable RXFIFO
ScibRegs.SCIFFTX.bit.SCIRST = 1; // 1:resume FIFO, 0: reset FIFO
ScibRegs.SCIFFTX.bit.SCIFFENA = 1; // enable FIFO
ScibRegs.SCICTL1.all = 0x23; // Enable RX and TX, enable SCI
add_task("scib_soft_fifo", soft_fifo_1ms_task, FOREGROUND_TASK, 1, 0);
}
static void soft_fifo_1ms_task(void)
{
uint16_t i;
// --------------------------------------------------------------------
if(ScibRegs.SCIRXST.bit.RXERROR)
{
// writing a zero to SWRESET to clear FE OE PE RXERROR
ScibRegs.SCICTL1.bit.SWRESET = 0;
// re-enable SCI by writing a 1 to SWRESET bit
ScibRegs.SCICTL1.bit.SWRESET = 1;
}
// --------------------------------------------------------------------
while(ScibRegs.SCIFFRX.bit.RXFFST)
{
uint8_t rxd = ScibRegs.SCIRXBUF.bit.SAR;
if(ScibRxFifo.ElementNum < 2*ArrLen(ScibRxFifo.Buffer))
{
packed_byte_array_set(ScibRxFifo.Buffer,
ScibRxFifo.EnqueueIndex,
rxd);
ScibRxFifo.EnqueueIndex ++;
ScibRxFifo.EnqueueIndex %= 2*ArrLen(ScibRxFifo.Buffer);
ScibRxFifo.ElementNum ++;
}
}
// --------------------------------------------------------------------
for(i=0; i<16; i++)
{
if(ScibRegs.SCIFFTX.bit.TXFFST < 16)
{
uint8_t txd;
if(ScibTxFifo.ElementNum)
{
txd = packed_byte_array_get(ScibTxFifo.Buffer, ScibTxFifo.DequeueIndex);
ScibTxFifo.DequeueIndex ++;
ScibTxFifo.DequeueIndex %= 2*ArrLen(ScibTxFifo.Buffer);
ScibTxFifo.ElementNum --;
ScibRegs.SCITXBUF.bit.TXDT = txd;
}
}
else
{
break;
}
}
}
void scia_init(uint32_t baud_rate)
{
uint16_t prescale = (uint16_t)(get_clock_freq() / 4 / baud_rate / 8 - 1);
SciaRegs.SCICTL1.all = 0x00; // reset SCI
SciaRegs.SCICCR.all = 0x07; // 1 bit stop, disable parity, idle mode, 8 bits data
SciaRegs.SCIHBAUD.bit.BAUD = prescale / 256;
SciaRegs.SCILBAUD.bit.BAUD = prescale % 256;
SciaRegs.SCIFFRX.bit.RXFIFORESET = 1; // 1:enable RXFIFO
SciaRegs.SCIFFTX.bit.SCIRST = 1; // 1:resume FIFO, 0: reset FIFO
SciaRegs.SCIFFTX.bit.SCIFFENA = 1; // enable FIFO
SciaRegs.SCICTL1.all = 0x23; // Enable RX and TX, enable SCI
add_task("scia_soft_fifo", soft_fifo_1ms_task, FOREGROUND_TASK, 1, 0);
}
static void soft_fifo_1ms_task(void)
{
uint16_t i;
// --------------------------------------------------------------------
if(SciaRegs.SCIRXST.bit.RXERROR)
{
// writing a zero to SWRESET to clear FE OE PE RXERROR
SciaRegs.SCICTL1.bit.SWRESET = 0;
// re-enable SCI by writing a 1 to SWRESET bit
SciaRegs.SCICTL1.bit.SWRESET = 1;
}
// --------------------------------------------------------------------
while(SciaRegs.SCIFFRX.bit.RXFFST)
{
uint8_t rxd = SciaRegs.SCIRXBUF.bit.SAR;
if(SciaRxFifo.ElementNum < 2*ArrLen(SciaRxFifo.Buffer))
{
packed_byte_array_set(SciaRxFifo.Buffer,
SciaRxFifo.EnqueueIndex,
rxd);
SciaRxFifo.EnqueueIndex ++;
SciaRxFifo.EnqueueIndex %= 2*ArrLen(SciaRxFifo.Buffer);
SciaRxFifo.ElementNum ++;
}
}
// --------------------------------------------------------------------
for(i=0; i<16; i++)
{
if(SciaRegs.SCIFFTX.bit.TXFFST < 16)
{
uint8_t txd;
if(SciaTxFifo.ElementNum)
{
txd = packed_byte_array_get(SciaTxFifo.Buffer, SciaTxFifo.DequeueIndex);
SciaTxFifo.DequeueIndex ++;
SciaTxFifo.DequeueIndex %= 2*ArrLen(SciaTxFifo.Buffer);
SciaTxFifo.ElementNum --;
SciaRegs.SCITXBUF.bit.TXDT = txd;
}
}
else
{
break;
}
}
}
我们以相同的方式初始化 SCIA 和 SCIB、SCIA 函数正常。 但是、SCIB 只能发送消息、而无法接收消息。 我们在 SCIB 接收引脚之前测量了波形、波形准确且正常。 不过、SCIB 接收 FIFO 总是保持为0、表示没有接收到消息。 如何解决该问题？
