FMC NOR is extremely slow !

[ranran]

Hello,

I run the FMC nor example for stm32h743 eval, with the eval board, and I get very poor timing:

I used the original configuration , and only changed DataSetupTime   from 8 to 10 (with the original configuration, the test fails with my eval board ! ).

Yet, the write speed of NOR flash is extremely slow:

Writing 64KB took 3 minutes and 10 seconds --> speed is 360 B/sec !

Does it make sense that nor write is so slow ? Is it the HW write speed or ineffective write routine (or both) ?

Thank you,

ran

Is there any idea ?

Thanks

ran 

[Tesla DeLorean]

>>I wander if anyone tested this example before it was packaged in the cube , or maybe it is that the timing is just too much close to limits of functional.

I'm not sure any aimless walking was involved, but testing of HAL and CubeMX is somewhat sporadic, and effort is expected to get the code examples to a point where they are robust enough for industrial/commercial application. Assume it is cut-n-paste grade development.

I've seen you use a term a couple of times which in the US/UK is interpreted as an odd word usage.

Wander (walk aimlessly, day-dream) != Wonder (think or speculate curiously)

[ranran]

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[ranran]

Hi Clive,

Is there a way to get the correct values for the FMC nor flash by ST ?

Thanks

[ranran]

Hello,

Can ST please provide the correct timing for this interface.

I managed to make it functional by increasing the numbers, but it seems that the flash takes very long time now....

What are the optimal values and how can I find them ?

Thank you,

ran

[Mohamed Aymen HZAMI]

Hello,

I already tested on my side and it works well.

Best Regards,

Mohamed Aymen.

[Tesla DeLorean]

The oddness here is that the external loaders (Keil, ST-LINK) can access the NOR fine, with what looks like the same timing settings, but STM32Cube_FW_H7_V1.3.0\Drivers\BSP\STM32H743I_EVAL\stm32h743i_eval_nor.c and calling BSP_NOR_Init() doesn't seem to provide data properly at 0x60000000 memory window.

What revision of EVAL board are you using, and what stepping of H7 silicon?

[ranran]

Hi,

Eventually I used the original configuration , and only changed

DataSetupTime   from 8 to 10 (with the original configuration, the test fails!).

Yet, the write speed of NOR flash is extremely slow:

Writing 64KB took 3 minutes and 10 seconds --> speed is 360 B/sec !

Does it make sense that nor write is so slow ? Is it the HW write speed or ineffective write routine (or both) ?

Thank you,

ran

[Tesla DeLorean]

I haven't timed it, but I was writing over 1MB, and it took in the order of 10-20 seconds at most.

Unfortunately this isn't something I can commit resources too.

[ranran]

Hi Clive,

But did you use the same test from cube I'm using , or did you use other external tool ?

I use examples/FMC/CFMC_NOR test, I just changed the size of buffer in example to 127*512 (= 127 KBytes).

Maybe it's the verification that takes so much time ?

I try to understand what can eplain this large time of writing in the example.

Thank you,

ran