SDRAM connections on FMC

[charles239955]

Posted on August 18, 2016 at 17:55

Hi,

Hoping for some feedback from ST or others who have tested/used this configuration...The datasheet for the STM32F745xx (also the 746xx) contains Table 11. This shows the FMC pin definition, and lists the following pins for use with SDNWE:PC0PH5Searching through the datasheet I have found that in Table 10 (Pin and Ball Definition) it lists FMC_SDNWE as an alternate function for PA7. However PA7 is not included in the FMC pin definition table.My question is: can PA7 be used for the FMC_SDNWE signal? There's either an error in Table 10 or an omission from Table 11.Thanks.

[Tesla DeLorean]

Posted on August 18, 2016 at 18:12

It is identified in Table 10 and Table 12, and only missing from Table 11. It is this way in several F7 Data Sheets. I'd say it is just missing from Table 11 due to an oversight. Will push to moderation for confirmation.

[charles239955]

Posted on August 18, 2016 at 18:22

Hi clive1

The STM32F745 datasheet also has a Section 1.1 regarding pin compatibility. It states that various packages are ''fully pin-to-pin compatible with the STM32F4xxxx devices''If the datasheet for the STM32F427/9 is consulted, it does NOT show PA7 as having an alternate function for FMC_SDNWE. This would mean that the pin compatibility statement is incorrect???Thanks again for your input clive1

[Tesla DeLorean]

Posted on August 18, 2016 at 18:32

PA7 is on the STM32F469xx with FMC_SDNWE functionality

I think the statement relates to migrating F4 to F7 not the other way around, and the AF muxing options have evolved.

[charles239955]

Posted on August 18, 2016 at 18:52

Ah OK thanks clive1. That's a very subtle point that - in my opinion - should be made clearer in the datasheet.

Hopefully the moderators will at least update Table 11 to include the extra FMC connection options.@ST: I have only discovered this (I have been using Table 11 until this point) now that my hardware is being fabricated. This has directly influenced my package choice and the overall size of the finished product!!! Please correct this to prevent future confusion.