Timing Parameters For SDRAM with RT1176 MCU

[Wobaffet]

Hello,

We wanted to clarify some things regarding the configuration of SDRAM for the RT1176 MCU.

For the cm7_semc example on the RT1170-EVK SDK, the SDRAM tAct2Act parameter is configured as below;

    sdramconfig.tAct2Act_Ns            = 2; /* tRC/tRDD 2ns */

For the SDRAM on EVK, tRC given as below:

tRDD value is not given on the datasheet for winbond, so how is it determined with 2ns?

Thank you in advance!

Best Regards.

[iabdalkader · Accepted solution]

Those values could be wrong, in the datasheet the units for tWR/tRDD are in tCK units, so at 160MHz it should be ~12ns, which is more inline with parts from other manufacturers (for example AS4C4M16SA lists this value as 12ns). Note, older boards seem to have this value generated correctly, for example

EVKB1060:

sdramconfig.tWriteRecovery_Ns = 12; /* 12ns */

EVK1170:

sdramconfig.tWriteRecovery_Ns = 2; /* tWR 2ns */

[ramprakash09]

Hi,

It look like you are trying to configure the SDRAM for the RT1176 MCU and you are unsure about the tAct2Act parameter. The tAct2Act parameter is typically determined by the SDRAM manufacturer and should be specified in the SDRAM datasheet. If the tRDD value is not given in the datasheet, it is usually safe to assume a value of 2ns, as this is a common value for many SDRAMs.

So It is important to note that this value can vary depending on the specific SDRAM being used. If the exact value is critical for your application, I would recommend reaching out to the SDRAM manufacturer directly for clarification.

Regards