Feature request: Programmable logic
I am a fan of STM32, especially the peripheral sets offered are great. Over the years however, one type of peripheral is missing which would be a great help for many projects, this is a programmable logic cell.
Such a cell would contain elements like Flip-Flops, Look Up Tables and such that can be configured for specific functions. For instance using the LUT's, it would be possible to create all kinds of logic operations like AND, OR, XOR gates.
Using the Flip-Flops, I would be able for instance to create a clock gate, which I needed in my last project. There I needed an external clock signal to propagate to other peripherals and be able to enable/disable this. In the end I manage to create this function with a timer but this unfortunately generates something like 9 clock cycles of latency limiting the maximum frequency of the external clock signal. A basic Flip-Flop solution would probably introduce a much smaller latency.
Competing products offer this kind of functionality more and more, for instance the Microchip SAMD51 offers a Custom Logic cell which is highly programmable.
Such a peripheral would offer inputs and outputs that can be connected to other peripherals (GPIO, Timers and so on). Here I do see an issue since the Peripheral Interconnect of STM32 is not quite generic but very specific for the different types of peripheral. Another consideration would be to add so called hardware event channels to the STM32 which allow connecting almost any peripheral event output to another peripheral event input.
Well forgive me for starting to design, just adding the programmable logic would be really great for many control oriented applications.