November 17, 2020
STM32F4xx chips
There are a whole gang of these with different quotas of this and that.
They all have an ARM Cortex-M core of some kind.
The following is not a comprehensive review, but just an overview of various
chips that I have been involved with.
STM32F405RGT6
This is what is on my Olimex-P405 board.
It seems to be the big boy of the series.
- Arm Cortex-M4 CPU with DSP and FPU
- 168 MHz CPU
- 1 Mbyte of Flash memory
- 192K of RAM
There is also a F405OE with only 512M of flash.
STM32F415
This seems to be the same as the F405, but "integrates a crypto/hash processor".
STM32F407
This seems to be identical to the F405.
It is available with either 512K or 1M of flash. Always 192K of ram.
There is also a 417 that adds the crypto processor.
The only difference I can see is that the F407 adds ethernet.
STM32F427/437
ST likes to offer these parts in "pairs" presenting the reader with the puzzle of
figuring out what is different about a 437. In this case the puzzle still stands unsolved.
To my surprise, this seems to be the big brother of the F4 series:
- 180 Mhz CPU
- 1M or 2M of Flash (but perhaps in banks)
- 256K of RAM
It even has an LCD-TFT controller, to offload the processor and provide graphics acceleration.
The way to get your hands on one of these is to buy a "discovery board" from Mouser for $30.
This gives you a STM32F429ZIT6 part, which does have 2M of flash, along with a 64Mbit SDRAM (8M)
a gyroscope and an LCD, which makes it an interesting package. They say it has an onboard ST-Link.
The LCD is a 2.4 inch QVGA unit, which is probably 320x200.
They boast that it is "Mbed enabled".
STM32F411
This seems to be the "little brother" of the F4 series.
You get 256K or 512K of flash and "up to" 128K of ram.
The Cortex M4 core runs at 100 Mhz.
You do get FPU and DSP.
STM32F401
This seems to be an even "littler brother", giving you 256K flash and 64K of ram.
The CPU runs at 84 Mhz. You do get the M4 core with FPU and DSP.
Black Pills
Some Black Pills from China are just Blue Pills with an STM32F103 and a black PCB.
The true "black pill" boards from China give you either an F401CCU6 or an F411CEU6.
These are very likely not genuine ST parts, but Chinese clones, but who knows.
- STM32F103C8T6 ARM Cortex-M3 MCU @ 72 MHz with 64KB flash memory, 20KB SRAM.
- STM32F401CCU6 Arm Cortex-M4F MCU @ 84 MHz with 256 KB flash, 64KB SRAM
- STM32F411CEU6 Arm Cortex-M4F MCU @ 100 MHz with 512KB flash, 128KB SRAM
My black pills just arrived and they are indeed marked STM32F411CEU6.
STMH743
Note that the letter is now "H" in lieu of "F" (I have also seen "L").
The H743 is a big brother to the H750 in the same family.
Note that there are both F7 and H7 parts. The F7 parts typically run
at 216 Mhz, while the H7 run at 480 Mhz. It uses a 40nm process rather
than a 90nm process.
The H743 runs at 480 Mhz, has I and D cache, has an M7 core with MPU, FPU, and DSP.
These come with 1M of ram and either 1M or 2M of flash.
The chip includes ethernet, but not all boards provide a connector.
A very affordable and nice option is a Nucleo-H743ZI2 from Mouser for $27
This has an integrated ST-Link and ethernet and are part of a family of "Nucleo-144" boards.
The chip is an STM32H743ZIT6U. The "I" in the part number indicates it has 2M of flash.
A "G" would indicate 1M of flash.
What first got me started on all of this was discovering some inexpensive boards
on AliExpress. They want $24 including shipping and their board does not include
ethernet, making the board from Mouser a much better choice.
Feedback? Questions?
Drop me a line!
Tom's Computer Info / [email protected]