topic Custom P2041 board DDR problem in P-Series

Custom P2041 board DDR problem

ayhmi — Tue, 30 Jun 2015 07:32:38 GMT

Hello,

We are using a custom P2041 board. We were working with u-boot without a problem for 2 months. Last week with no reason u-boot hangs on DDR initialization. After i debugged i realized that DDR controller initialization passes (D_INIT bit is cleared) but read/write procedures to RAM fails. I mean i can't read the same data i wrote.

I checked my board and observed that P2041 sends constantly DDR reset to RAM modules. I can think source of the problem may be following:

- SDRAM hardware problem

- P2041 hardware problem

- DDR controller initialization problem (It was working before)

We are using 5xISSI IS43TR16512A-15HBLI 512Mx16 8Gb DDR3 SDRAM with ECC. If anyone experienced similar problem please help me to determine the source of problem.

Thanks

Re: Custom P2041 board DDR problem

Bulat — Tue, 30 Jun 2015 13:09:35 GMT

As far as I know P2041 does not have dedicated "DDR reset" signal. When you observed that P2041 sends constantly DDR reset to RAM modules, which P2041 signal you checked? Or more general, how DDR reset is generated on your board?

Regards,

Bulat

Re: Custom P2041 board DDR problem

ayhmi — Thu, 02 Jul 2015 05:34:06 GMT

I am sorry i misjudged the situation. Yes you are right Bulat. Hardware signals seem correct. However RAM data changes between 2 memory reads.