LPC Microcontrollers中的主题 Re: LPC54S018's UART : how to force parity bit ?

LPC54S018's UART : how to force parity bit ?

belmontbob59 — Fri, 31 Jan 2020 18:03:40 GMT

I need to force the parity bit when transmitting data via USART. Older NXP MCUs (LPC17xx, LPC18xx) have 4 options for parity setting. Example for LPC17xx:

However, LPC54s018 does not:

I thought about using the 9th bit by setting DATALEN to 2, but the FIFO write data register only accepts 8bits.

Please advise.

Re: LPC54S018's UART : how to force parity bit ?

belmontbob59 — Mon, 03 Feb 2020 17:16:32 GMT

Never mind, FIFOWR is 9bit wide. However, Please note a shortcoming in the SDK's fsl_usart.h, the API does not allow for 9bits data transfer. (only 7 or 8bits are allowed):

Re: LPC54S018's UART : how to force parity bit ?

Omar_Anguiano — Tue, 04 Feb 2020 19:03:08 GMT

Hello bob belmont

Although the enum only enumerates until 8bits you can add a variable to add the 9bit. The usar_data_len_t gets written at the CFG register. So writing a 2 will allow the 9bit transfer.

Let me know if this is helpful.

Best Regards,

Omar