Receiving Moren Than 16 Data via USART

fatihozen — Thu, 27 Aug 2020 11:38:28 GMT

Hi,

I am using LPC54608J512BD208. I have a custom desktop application sends me data through USART. Some packets sends to MCU are greater than 16 datas and I can see just first 16 datas, others are empty. I used logic analyzer and I see that PC application is sending all bytes. The issue is on MCU side. I can't configure PC app to send me less than 16 datas so I have to do something with LPC546. What should I do ? I checked FIFOSTAT, it is 1000f2. So that means RX FIFO is full. How can I emtpy it and then receive other datas ?

void InitializeUart(void)
{
usart_config_t config;
USART_GetDefaultConfig(&config);
config.baudRate_Bps = 9600;
config.enableRx = true;
config.enableTx = true;
IOCON->PIO[3][16] = 0x0301;
IOCON->PIO[3][17] = 0x0301;
CLOCK_AttachClk(kFRO12M_to_FLEXCOMM8);
USART_Init(USART8, &config, CLOCK_GetFreq(kCLOCK_Flexcomm8));
}

This is my reading data routine:

void USART_Read(USART_Type *base, uint16_t *data, size_t length)
{
for (; length > 0; length--)
   {
      *data = base->FIFORD;
      data++;
   }

}

I have tried something like this but nothing changed:

void USART_ReadBlocking(USART_Type *base, uint16_t *data, size_t length)
{
int i = 0;
for (i = 0; i < 16; i++)
   {
   *data = base->FIFORD;
   data++;
   }

base->FIFOCFG |= USART_FIFOCFG_EMPTYRX_MASK;

for (i = 0; i < 16; i++)
   {
   *data = base->FIFORD;
   data++;
   }
}

Re: Receiving Moren Than 16 Data via USART

FelipeGarcia — Wed, 02 Sep 2020 16:32:32 GMT

Hello,

I highly recommend you to refer to our SDK examples. In our USART examples there is implementation of clearing FIFO in case RX FIFO error occurred in USART_ReadBlocking.

/* check rxFIFO statusFlag */ if ((base->FIFOSTAT & USART_FIFOSTAT_RXERR_MASK) != 0U) { base->FIFOCFG |= USART_FIFOCFG_EMPTYRX_MASK; base->FIFOSTAT |= USART_FIFOSTAT_RXERR_MASK; status = kStatus_USART_RxError; break; }

Best regards,

Felipe

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Receiving Moren Than 16 Data via USART

Re: Receiving Moren Than 16 Data via USART