[LPC845] Avoid repeated stop-start bits in UART transmision

[jjvicente]

Hi,

I need to send bigger-than-8-bit frames via UART (16, 24 and 32 bits). These frames must include just one start bit and one stop bit at the end of the frame. Just one on each side.

I've checked that the USART peripheral includes a pair of stop-start bits at the end of each 8 bits string (I know I can change the USART to transmit 7 to 9 bits, but it doesn't help either way). Thus, it distorts the structure of the whole frame inserting these non-wanted bits in the middle of the frame.

Is there any way to disable the start and stop bits automatic generation in the USART peripheral?

Is there any other option to send this kind of big frames using the USART peripheral? I'd like to avoid doing it manually with a GPIO...

Thanks and regards,

Juanjo

[EdwinHz]

Hi @jjvicente,

The USART module for the LPC845 is designed to transmit only 7, 8 or 9 data bits per frame. The only way of sending a frame with more bits than this would be to implement it manually via GPIOs.

I apologize for the inconvenience this may cause.

BR,
Edwin.