Replace STM32F215ZG with pin compatible MCU with more flash and RAM

[AndyCrosher]

Can anybody suggest a pin compatible ST micro that has more Flash and RAM than the STM32F215ZG - this has 1MB Flash and 256Kb of RAM. I have to maintain large data structures and I keep running out of space.

[Andrew Neil]

How much more ?

[STTwo-32]

Hello @AndyCrosher and welcome to the ST community :smiling_face_with_smiling_eyes:.

I suggest you use the CubeMX that will list pin-compatible parts (with flash and ram details of each MCU).

Load your chip, configure it if you want, then go to Pinout -> List Pinout Compatible MCUs:

Best Regards.

STTwo-32

[AndyCrosher]

Hello Andrew,

I have seen some STM32F4 series chips have 386Kb of ram and 2Mb of flash space - this should be sufficient.

Regards Andrew.

[STTwo-32]

Here are some STM32F4 that can do the job:

If you want to have more details, please refer to my first comment.

Best Regards.

STTwo-32

[waclawek.jan · Accepted solution]

AFAIK, the 'F20x has only 128kB RAM (64kB CCMRAM and 64kB SRAM1).

STM32F427/429ZI has 2MB FLASH, 64+192=256kB RAM and - contrary to 'F469 - is almost completely pin- and functionally compatible with 'F20x (check pin 143, and the VBAT divider is different).

JW

[Tesla DeLorean]

Pretty sure the F2's lacked CCM

But the 144-pin parts had a bunch of cross compatible options, up thru the F7 an H7 parts.

There were a couple of F2 pins that needed to be jumper differently on F4's but this was well documented over a decade, and was typically accommodated at the design phase. I could build my boards with any of the F205, F215, F405 or F415 parts with a couple of BoM changes.

[waclawek.jan]

> Pretty sure the F2's lacked CCM

I stand corrected, thanks. The 128kB total RAM holds true, though.

> There were a couple of F2 pins that needed to be jumper differently on F4's

For the 144-pin part, I know only of pin 143 (which in 'F2 is much like "don't care" and PDR_ON in 'F4 with "funny" consequences if it's not connected as described by DS). Did not try/check deeply, but the VCC/VSS jumpers in 'F4 DS are IMO only for 'F1-'F4 compatibility.

While they may be (mostly or fully) pin-compatible, 'F7/'H7 (i.e. Cortex-M7) may also bring in surprises to unaware. 'H7 also has quite different peripherals such as SPI or DMA.

'L4+ (STM32L4S5) may be also an interesting option to look at, especially from the RAM perspective, if the peripheral mix will fit the requirements (i.e. there's no need for the dual-port DMA, two OTGs nor ETH, etc.)

JW

[Tesla DeLorean]

If don't recall if the design guide was in the F2 or F4 data-sheets. But involved like 2 pins in pull up/down configurations.

[waclawek.jan]

Pin listings for STM32xxxZIT (i.e. 2MB FLASH, 144 QFP) in attached spreadsheet.

It does not guarantee functional compatibility, of course.

JW