On 4/15/2020 1:51 PM, Gregory Nutt wrote:
This helps clarify the families: https://en.wikipedia.org/wiki/STM32
"The STM32 F3-series is the second group of STM32 microcontrollers
based on the ARM Cortex-M4F core. The F3 is almost pin-to-pin
compatible with the STM32 F1-series. ...
"The STM32 F2-series of STM32 microcontrollers based on the ARM
Cortex-M3 core. It is the most recent and fastest Cortex-M3 series.
The F2 is pin-to-pin compatible with the STM32 F4-series ...."
The original F3's (2012) were little more than F1's with a Cortex-M4.
Some peripherals were upgraded, but most were not. The early STM32F205
and STM32F207 were identical to the STM32F405 and STM32F407, except with
the Cortex-M3. What has happened over the years is that the Cortex-M4
platforms have evolved and advanced, but the the Cortex-M3 platforms
have not advanced so much. I did the ports and most of the drivers for
all initial versions of these parts and feel confident in saying these
things, but I am not so familiar with the more recent variations. It
appears to me that the F3 has taken its own path.
