SDRAM Read operation bug when using HAL libraries.

dhavalhparikh26 · ‎2014-07-16

Posted on July 16, 2014 at 20:12

Hello All,

I was trying to write and read data from SDRAM on the STM32f429- Discovery board.

I was able to write data to the SDRAM but the read operation was not working.

I used the STM32Cube Mx utility to generate the initialization code.

I started comparing the initialization code with the one which are in the BSP libraries and the FMC example which comes with the STM32CubeF4.

I noticed that the Speed of the GPIO which were used for SDRAM were set to ''LOW'' when STM32CubeMx generated the initialization code. But they were set to ''HIGH'' in the BSP libraries.

As simple as it looks, I think speed is critical when reaading data from SDRAM and this can be easily overlooked.

ST should correct this in the next update of the HAL libraries because the read operation doesn't work without it.

#discovery #stm32f4 #!bug #sdram

stm32cube-t · ‎2014-07-21

Posted on July 21, 2014 at 19:07

Hello,

with MX version 4.3, the gpio output speeds are set to the maximum output speed in the stm32f4xx_hal_msp.c file [FMC SDRAM configuration].

Can you please confirm your settings or send us the ioc file so that we can reproduce your configuration.

Thank you.

dhavalhparikh26 · ‎2014-07-22

Posted on July 22, 2014 at 19:12

Hello,

Please find the .ioc file attached. I checked the GPIO settings in the configuration and found that the FMC gpio speed is set to low for all.

Can't be this be set to ''high'' by default whenever the fmc is enabled?

If I'm doing any mistake in the configuration please correct me.

Thanks,

Dhaval.

________________

Attachments :

SDRAM_DMA_TRY_071414.ioc : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0zu&d=%2Fa%2F0X0000000bgk%2FQSoB2xv7AhxpsR_DVbY4QvjoXjxsZ6E1ZRnKm1fmDYU&asPdf=false

stm32cube-t · ‎2014-07-28

Posted on July 28, 2014 at 16:51

Hello,

I confirm the default settings in MX for FMC SDRAM GPIO speed is High.

You can easily update your current project with the proper GPIO speed settings: from the Configuration tab, select all FMC GPIO rows and change the speed at once.

Best regards

zekeriya · ‎2014-07-31

Posted on July 31, 2014 at 13:41

Thank you parikh.dhaval.

Your observation was very helpful.