TMS570LC4357: Question about extending flash and sdram through emif

Hi Yale,

Yale Li 李耀先 said:

how should I read, write and erase the FLASH? Is it to operate through the F021 API like the internal FLASH or directly read and write through the address? Are there any relevant routines that can be referred to?

F021 API is not required to access external NOR flash. You can directly access by read and write through the address.

You can refer below thread once, which have a example demo code for NOR Flash

(+) TMS570LS3137: only 16 MB accessible, NOR flash S29GL256S (32MB) - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Yale Li 李耀先 said:

2. For the external SDRAM, can I read and write it after I configure it according to Procedure A or Procedure B given in the chapter 21.2.5.5 SDRAM Configuration Procedure in TRM? Can it be manipulated directly by physical address?

Yes, you can access directly after doing the configuration. And there is an example project for SDRAM implementation in HALCoGen, you can refer it once before implementing.

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Thanks & regards,
Jagadish.

Thank you, Jagadish.

Another question:

When directly accessing the off-chip NOR FLASH through the address, is it necessary to perform an erase operation before each write, just like ordinary memory read and write operations?

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Thanks & Regards

Yale