F730 flash PSIZE vs. Supply voltage

[RMcCa]

I am a bit confused by the language in the F7 reference manual, section 3.3.5 (RM0431) that describes the flash program/erase parallelism. Does the power supply limit the maximum value of the parallelism or does it limit one to a particular size?

The caption for table 6 is "Table 6 provides the correct PSIZE​ values". Should it say "correct maximum PSIZE values"?

I am asking because i have been writing bytes to the flash with Vcc=3.3V and PSIZE = 0 and its been working fine for a while​, but i wonder if that's only luck and i should switch to 32bit writes. Speed is not an issue in this case.

[Uwe Bonnes]

"correct maximum PSIZE values" is the right thing

[waclawek.jan]

Uwe,

Can you please quote a source for this?

@Imen DAHMEN​ ,

Can this please be clarified, across all STM32 RMs?

Jan

[Imen.D]

@RMcCa​ , It's ok for your use case. I confirm, it is the max PSIZE vs Voltage.

I will raise this internally to update all STM32 RMs.

Edit: We suggest to change “Parallelism size�? to “max parallelism size�?.

Best Regards,

Imen

[RMcCa]

Thank you, good to know my code wasn't working by accident.​

[RMcCa · Accepted solution]

I know this is minor, but i also found a few copy & paste errors in stm32f7xx_hal_flash.c when i was looking for the answer. The @note in the comments is incorrect for FLASH_Program_Word​, Halfword & Byte.

[Uwe Bonnes]

The datasheet STM32F730x8 page 127, table Table 53. Flash memory programming (continued) seems quite clear to me.

[RMcCa]

Interesting. There is an additional mistake then. The datasheet list 3V max for 32bit programming while the RM says 3.3V.

[Uwe Bonnes]

Yes, the max value for 32-bit program operation seem wrong

[waclawek.jan]

Thanks, Imen.

Jan

@Imen DAHMEN​