Hi
>> Seems to be no interest to increase Pi4B uart to 32Mbaud
I better fix up my error, the uart clock can be raised to 750Mhz (46.875Mhz baud) or 640Mhz (nice neat 40Mhz baud).
I wrote a utility program to 1. write 32 bytes 2. poll busy bit 3. read 32 bytes with/without hardware loopback, 1 million iterations(35MB), bypassing the device IRQ and tty layer and can say the PLL01 is rock solid at ~24 and 20 Mhz. It is usable at 46/40 Mbaud with resend on error but only tried with loopback wire so far.
I'm thinking a 1500Mhz uart clock with the baud integer at divide by 2 (as stabiliser) might allow stable higher baud rate OR its at its limit (I think its rated 32Mbaud).
probably more sensible to use PICO to PICO for high speed serial
thanks Brian
>> Seems to be no interest to increase Pi4B uart to 32Mbaud
I better fix up my error, the uart clock can be raised to 750Mhz (46.875Mhz baud) or 640Mhz (nice neat 40Mhz baud).
I wrote a utility program to 1. write 32 bytes 2. poll busy bit 3. read 32 bytes with/without hardware loopback, 1 million iterations(35MB), bypassing the device IRQ and tty layer and can say the PLL01 is rock solid at ~24 and 20 Mhz. It is usable at 46/40 Mbaud with resend on error but only tried with loopback wire so far.
I'm thinking a 1500Mhz uart clock with the baud integer at divide by 2 (as stabiliser) might allow stable higher baud rate OR its at its limit (I think its rated 32Mbaud).
probably more sensible to use PICO to PICO for high speed serial
thanks Brian
Statistics: Posted by brianWS — Wed Jun 25, 2025 7:36 am