Is there any UART examples by directly accessing the registers?

Question

Is there any UART examples by directly accessing the registers? 
 Based on SDK15.0.2, for NRF52832 or NRF52810, higher freedom, higher memory utilization.

Jared · Accepted Answer

Hi,

There isn't one available in the SDK for UART but here is one for UARTE for nRF52840:

#include <nrf.h>

#define PIN_TXD        (6)
#define PIN_RXD        (8)

int main(void)
{
  uint8_t hello_world[] = "Hello World!\n";
  
  // Configure the UARTE with no flow control, one parity bit and 115200 baud rate
  NRF_UARTE0->CONFIG = (UART_CONFIG_HWFC_Disabled   << UART_CONFIG_HWFC_Pos) |
                       (UART_CONFIG_PARITY_Included << UART_CONFIG_PARITY_Pos); 
  
  NRF_UARTE0->BAUDRATE = UARTE_BAUDRATE_BAUDRATE_Baud115200 << UARTE_BAUDRATE_BAUDRATE_Pos;
  
  // Select TX and RX pins
  NRF_UARTE0->PSEL.TXD = PIN_TXD;
  NRF_UARTE0->PSEL.RXD = PIN_RXD;
  
  // Enable the UART (starts using the TX/RX pins)
  NRF_UARTE0->ENABLE = UARTE_ENABLE_ENABLE_Enabled << UARTE_ENABLE_ENABLE_Pos;
  
  // Configure transmit buffer and start the transfer
  NRF_UARTE0->TXD.MAXCNT = sizeof(hello_world);
  NRF_UARTE0->TXD.PTR = (uint32_t)&hello_world[0];
  NRF_UARTE0->TASKS_STARTTX = 1;
  
  // Wait until the transfer is complete
  while (NRF_UARTE0->EVENTS_ENDTX == 0)
  {
  }
  
  // Stop the UART TX
  NRF_UARTE0->TASKS_STOPTX = 1;
  // Wait until we receive the stopped event
  while (NRF_UARTE0->EVENTS_TXSTOPPED == 0);
  
  // Disable the UARTE (pins are now available for other use)
  NRF_UARTE0->ENABLE = UARTE_ENABLE_ENABLE_Disabled << UARTE_ENABLE_ENABLE_Pos;
  
  while (1)
  {
    __WFE();
  }
}

regards

Jared

Is there any UART examples by directly accessing the registers?

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