RPA tool - how to generate "relaxed" LPDDR4 timing?

[frank_vanhooft]

What's the best way to use the RPA spreadsheet tool to create "relaxed" LPDDR4 timing? By that I mean timings with more than the usual margin, to allow for more (component / temp / etc) variabilities?

I can think of two possible ways, but I don't know if one is better than the other, or even valid.

1. Specify a lower "clock cycle frequency" eg 1400 MHz instead of the default 1500 MHz. Then put a corresponding value in the "DDR Stress Test File" tab DRAM_PLL_FDIV_CTL0 register cell for that frequency. So the bus runs at 1400 MHz using 1400 MHz timing values.

2. Leave the clock cycle frequency at 1500 MHz, and generate the register values for that. But edit the "DDR Stress Test File" tab DRAM_PLL_FDIV_CTL0 register cell for a lower freq, eg 1400 MHz. So the iMX8 runs the bus at 1400 MHz but uses 1500 MHz timing values.

Any comments or suggestions?

Thanks.

[frank_vanhooft]

In my question above, is either option, 1 or 2, better than the other? Or is there another, better, third option?

Thanks.

[Rita_Wang]

OK, I will help confirm, which product are you using, i.MX8MP or others?

[frank_vanhooft]

iMX8 Mini,  the MIMX8MM6DVTLZAA  

Thanks.

[Rita_Wang · Accepted solution]

@frank_vanhooft Here you need use the method 1 to generate timing.

If you want to change DDR clock, you should use new frequency DDR configuration and clock setting both at same time.

Hope this can do help for you

[Rita_Wang]

You can refer to this https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/iMX-8M-Mini-Register-Programming-Aid-DRA...