topic Re: LS1046 RESET_REQ_B problem in Layerscape

LS1046 RESET_REQ_B problem

gaborkocsis — Wed, 22 May 2019 10:37:50 GMT

Hello Everybody,

I have faced a weird phenomenon on our custom board based on an LS1046A.

In a CPLD I've implemented a power and reset sequence. I was able to bring up our board, the Linux runs correctly from the onboard eMMC,
BUT,

the LS1046's RESET_REQ_B constantly pulled down. During the reset sequence it goes high then goeas back low
Despite of this everything seems to be OK.

But I don't understand this phenomenon.

Has anybody faced this before?

thanks in advance,

Gabor

Re: LS1046 RESET_REQ_B problem

ufedor — Wed, 22 May 2019 11:34:08 GMT

Described behaviour means that there is an issue with RCW.

The first point to check is SerDes reference clocks - they should have correct frequencies and should be provided for all PLLs which are not explicitly powered down in the RCW.

In case of further question please provide the processor connection schematics as searchable PDF for inspection along with U-Boot log.

Re: LS1046 RESET_REQ_B problem

flashingsky — Fri, 30 Jul 2021 02:15:00 GMT

I meet the same problem.I'm very puzzled now.

If I used the RESET_REQ_B of LS1046A to trig a power on reset. LS1046A can not bring up.