Compute Module • Re: Compute Module 4 Tx/Rx FIFO size and RS485 support.

The BCM2711 on the CM4 has 1x mini UART with a 8/8 FIFO and multiple rev 2 Arm PL011 UARTs with a 16/16 FIFO. See
https://developer.arm.com/documentation ... /f?lang=en

1) What is the Compute Module 4 Rx and Tx hardware FIFO buffer size?

16/16. Rev 3 PL011 has 32/32 but we only have rev 2 which is 16/16.

2) Is the FIFO separate or is it shared for each UART?

Separate.

3) Does Raspberry Pi's CPU have a built-in half-duplex mode capable of automatically controlling line direction (ex. toggling RTS)? I mean does it support the Linux Kernel RS485 driver? https://docs.kernel.org/driver-api/seri ... rs485.html

There is CTS/RTS support. You should read https://github.com/raspberrypi/linux/issues/5578 first though.

Statistics: Posted by trejan — Thu Apr 11, 2024 12:32 am

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