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Altera_Forum
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19 years ago

Are Avalon UARTs useable as eCos /dev/tty ?

I can't get working correctly a simple application that reads bytes at 115200 bps under eCos using "hardware serial device driver" (Avalon UART) : I get one byte each two. However, the (almost...
Altera_Forum's avatar
Altera_Forum
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19 years ago

Hi Fred,

I had something similar to this happening to me. Whilst Rxing at higher Baud rates (including 115200) I would occasionally lose characters. It turned out to be a timer interrupt, of higher priority, occasionally taking longer to complete. If the timer interrupt lasted more than 400uS then that was long enough for the UART to Rx 2 characters, one in the holding register and one in the shift register - anything else has nowhere to go.

I fixed the problem by giving the UART a higher priority in the SOPC builder, this didn't cuase any problems, for me, as the UART irq is very fast - just buffers the character into a ring buffer for later processing.

Banx.