dig--02715-001

Hi Alex,

What's the intent behind using the main UART for mcu UART prints?

Regards,
Parth

The intention is not to get prints instead is to use a peripheral device which will be connected on main UART1 and the binary would be MCU domain. I was able to communicate with 115200 baudrate with above changes but I want to use 921600 and I am just seeing junk prints with 921600 baud rate. 

Hi Alex,

Can you try adding params.baudRate = baudRate; before UART_open in UART_stdioInit at <PDK>\packages\ti\drv\uart\src\UART_stdio.c

Regards,
Parth

Hi Parth,

Thanks for the response.

I have tried new baudrate by modifying the baudrate in UART_defaultParams structure which I believe would have the same impact since UART_Params_init is fetching the configuration paramters based on UART_defaultParams structure. 

. Please see the code snippet below. 

I have observed the divisor calculation is based on the clock frequency, baudrate, operating mode and UART_MIR_OVERSAMPLING_RATE_42 (Over-sampling rate for MIR mode used to obtain the Divisor Values). Do we need to take care of any of these parameters. I am using the following for now

• baudrate = 921600
• frequency = 48MHz(also tried with 96Mz)
• Operating mode = UART16x_OPER_MODE
• Over-sampling rate for MIR mode used to obtain the Divisor Values = UART_MIR_OVERSAMPLING_RATE_42

Regards, 

Alex

Hi Alex,

I believe that just changing the baudrate should be enough, the driver should take care of the rest. Did you get a chance to try this out? Are you seeing proper prints with this?

Regards,
Parth

Hi Parth,

Parth Nagpal said:

Can you try adding params.baudRate = baudRate; before UART_open in UART_stdioInit at <PDK>\packages\ti\drv\uart\src\UART_stdio.c

I believe changing the baudrate in UART_defaultParams structure will have the same behavior as adding params.baudRate = baudRate.  

I have even tried by the way you suggested but still I am only seeing junk prints.

Do we need to take care of anything else in software?

Hi Alex,

Can you please share a patch of changes that you have done? I'll check it and try to reproduce the issue on my end.

Regards,
Parth

Hi Parth,

I also tried with different baudrate on MCU uart, there also I was getting junk prints. I am not using apputils here instead I am using UART_printf function.

• In board_utils.c
  Modified highlighted  
  Board_initParams_t gBoardInitParams = {BOARD_MCU_UART_INSTANCE, BOARD_SOC_DOMAIN_MCU, BOARD_PSC_DEVICE_MODE_NONEXCLUSIVE, BOARD_MAIN_CLOCK_GROUP_ALL, v BOARD_MCU_CLOCK_GROUP_ALL};
                                        
• In UART_stdio.c
  Added the highlighted line
  void UART_stdioInit(uint32_t value)
  {
      UART_Params         params;
      SemaphoreP_Params   semParams;
      char                semName[] = "uartStdio";
  
      if(uart_stdio.uart_handle==NULL)
      {
        UART_init();
  
        UART_Params_init(&params);
        
        params.baudRate = 921600;
        
        uart_stdio.uart_handle = UART_open(value, &params);
  
        /*
         * Construct thread safe semaphore for UART_printf
        */
        UART_osalSemParamsInit(&semParams);
        semParams.mode = SemaphoreP_Mode_BINARY;
        semParams.name = semName;
        uart_stdio.sem = UART_osalCreateBlockingLock(1U, &semParams);
      }
  }
  
• In UART_drv.c
  Modified highlighted  
  void UART_init(void)
  {
      if (UART_count == (-((int32_t)1))) {
          /* Call each driver's init function */
          for (UART_count = 0; UART_config[UART_count].fxnTablePtr != NULL; UART_count++) {
              UART_config[UART_count].fxnTablePtr->uartInitFxn((UART_Handle)&(UART_config[UART_count]));
          }
      }
  
  #if defined (BUILD_MCU)
      // UART_socInit();
  #endif
  }

Thanks & Regards,

Alex