UART Configuration on NRF52-DK(bare metal programming)

RE: UART Configuration on NRF52-DK(bare metal programming)

Kenneth — Thu, 21 Nov 2019 07:54:43 GMT

The clock to the peripheral is always 16MHz, the baudrate is configurable through:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/uart.html?cp=4_2_0_49_9_11#register.BAUDRATE

The 16MHz clock accuracy depend on the HFCLK source:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/clock.html?cp=4_2_0_18_2_3#register.HFCLKSTAT

RE: UART Configuration on NRF52-DK(bare metal programming)

Hari Elamadu — Thu, 21 Nov 2019 05:40:11 GMT

Hi,

how can I configure the clock for UART, I didn't find any information related selection of clock for UART.

RE: UART Configuration on NRF52-DK(bare metal programming)

Hari Elamadu — Tue, 19 Nov 2019 09:55:32 GMT

I have tried the second method(without the driver) but it was not worked, the TASKS_STARTTX is it a register?

I have implemented the below code please check is my understanding is correct?

#define UART_BASE 0x40002000
#define PSEL_RTS (*((uint32_t*)(UART_BASE + 0x508)))
#define PSEL_TXD (*((uint32_t*)(UART_BASE + 0x50C)))
#define PSEL_CTS (*((uint32_t*)(UART_BASE + 0x510)))
#define PSEL_RXD (*((uint32_t*)(UART_BASE + 0x514)))
#define RXD_BUFF (*((uint32_t*)(UART_BASE + 0x518)))
#define TXD_BUFF (*((uint32_t*)(UART_BASE + 0x51C)))
#define UART_ENABLE (*((uint32_t*)(UART_BASE + 0x500)))
#define UART_CONFIG (*((uint32_t*)(UART_BASE + 0x56C)))
#define UART_BAUD (*((uint32_t*)(UART_BASE + 0x524)))
#define TASKS_STARTTX (*((uint32_t*)(UART_BASE + 0x008)))
#define EVENTS_TXDRDY (*((uint32_t*)(UART_BASE + 0x11C)))

UART_ENABLE = 0x08; //enable UART_ENABLE
EVENTS_TXDRDY &=~(0xFFFFFFFF);
TASKS_STARTTX = 1;
TXD_BUFF ='A';

RE: UART Configuration on NRF52-DK(bare metal programming)

Kenneth — Mon, 18 Nov 2019 12:29:10 GMT

Have you considered using the UART driver instead?
https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/hardware_driver_uart.html?cp=6_1_2_0_19

If you don't want to use the driver, then make sure that you use the STARTTX task to start transfers and clear TXDRY events as shown in the UART transmission figure:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/uart.html?cp=4_2_0_49_3#concept_xpv_ftw_sr