Missing SDRAM choice in STM32Cube for 100 pin package

[omeryaman]

Posted on April 08, 2018 at 12:45

Hello everyone,

I want to use 100pin STM32F446 or STM32F722 microcontroller to drive an SDRAM. Bu in STM32Cube it doesn't have an SDRAM choice in FMC peripheral. When i select a 144pin version of these microcontrollers the SDRAM choice appears in STM32Cube.  So do i have to use a 144pin package to drive an SDRAM in FMC module instead of 100 pinned one

#sdram #fmc #stm32f4 #stm32cube #stm32f7

[Tilen MAJERLE]

Posted on April 08, 2018 at 13:15

STM32F722 does not have all GPIO pins available for SDRAM.

[omeryaman]

Posted on April 08, 2018 at 13:25

So do i have to use 144pinned version instead of 100pinned one?

[Tesla DeLorean]

Posted on April 08, 2018 at 14:42

If you review the parts data sheet you should be able to confirm this yourself. Might be an important thing to start with if you are designing a board.

[omeryaman]

Posted on April 08, 2018 at 16:16

One uc that i may use is STM32F446VC. In its datasheet there is a note for FMC:

- For the LQFP100 package, only FMC Bank1 or Bank2 are available. Bank1 can only support a multiplexed NOR/PSRAM memory using the NE1 Chip Select. Bank2 can only support a 16- or 8-bit NAND Flash memory using the NCE2 Chip Select. The interrupt line cannot be used since Port G is not available in this package.

The other uc that i may use is STM32F722VC. In it datasheet there is a note for FMC too:

- For the LQFP100 package, only FMC Bank1 is available. Bank1 can only support a multiplexed NOR/PSRAM memory using the NE1 Chip Select.

These notes direct me to a 144pin package. Isn't it?

[Tesla DeLorean · Accepted solution]

Posted on April 08, 2018 at 17:47

It is a function of pin availability, SDRAM uses a lot of pins, and there are limited AF mux options, take a high-light marker and draw across the rows/columns of the 100pin device and SDRAM pins, this should indicate if the part choice is workable.

If the 144-pin LQFP is too large, consider the UFBGA packages

[omeryaman]

Posted on April 08, 2018 at 18:13

Hello Clive,

There are missing SDRAM pins in 100 pinned package as address pins. Thanks for your answer