TMS320F280049C: Clarification on Flash Memory Erase and Programming Speed

Chen-Chih Liu

Tool/software:

Dear Experts,

As we know, the erase/write/fetch speeds for Flash depend on FCLK, which is configured by the RWAIT register. However, I would like to confirm whether the speeds for erase, write, and fetch are calculated as SYSCLK / (RWAIT + 1).

For example, if SYSCLK is 100 MHz and RWAIT is set to 4, can I confirm that both erase and write speeds are 20 MHz?

If not, what are the actual speeds?

Thanks and regards,
CC Liu

over 1 year ago

+1 MatthewPate over 1 year ago

TI__Guru* 84390 points

CC,

Only the fetch/read speeds will be impacted by the RWAIT register when the flash is accessed by the CPU. This needs to be set according to the device speed such that the flash access time is met in the DS here:

https://www.ti.com/document-viewer/TMS320F280049C/datasheet#GUID-F1C35C53-5BF6-42A0-8580-DD44CCE0B9C2/TITLE-SPRS945SPRS8806876

Now, the program/erase times are set in the table right below the one above; the Flash API needs to know the CPU clock speed, but that is so it can give the correct timings to perform the program/erase correctly. The RWAIT should be configured correctly, but that would only impact the verify(read back) portion of the API calls. The program/erase timings themselves shouldn't be impacted by RWAIT.

Best,

Matthew

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F280049C: Clarification on Flash Memory Erase and Programming Speed