Compiler/PROCESSOR-SDK-AM335X: GPMC connection to SRAM

danny

Tool/software: TI C/C++ Compiler

hi,TI experts

I have a chip named IS62WV1288DBLL-45QLI which is a SDRAM need to be linked to the am335x gpmc, I look at the kernel code and did not find the relevant driver , is there any relevant information can refer to？

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

You will not find a driver for GPMC, as this interface is memory mapped. You need to setup the correct configuration and timings in the device tree and then directly read/write to the address you need.

0 danny over 6 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

Dear Biser,

thank you for your reply,but I'm a new person, I have no idea how to configure the timings,could I read the《Technical Reference Manual》 to get solution？

0 Biser Gatchev-XID over 6 years ago in reply to danny

TI__Guru**** 393215 points

Yes, this is section 7.1 in the TRM. Check also the documentation folders in the SDK.

0 danny over 6 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

Dear Biser,

thank you for your advice。I can read and wirte data to the chip now.but I want to save the data when the power is off.

I look at the chip's datasheet with data retention mode,I do not know how to implement that data retention waveform mode

0 Biser Gatchev-XID over 6 years ago in reply to danny

TI__Guru**** 393215 points

You can try switching the GPMC_CS to GPIO and toggle it as required.

0 danny over 6 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

Dear Biser,

thank you for your replay,we also connected the nand flash and DM9000 on the GPMC, if I switch the GPMC_CS,it would affected other functions

0 Biser Gatchev-XID over 6 years ago in reply to danny

TI__Guru**** 393215 points

I don't believe you have connected everything on one CS signal. Looking again at the timing diagrams, I think you will need some sort of external buffering powered from the SRAM supply in order to achieve this.

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Compiler/PROCESSOR-SDK-AM335X: GPMC connection to SRAM