I was working on a PCB design and I am stuck on a question over SPI communication over different voltages.
I am using some 74HC595 and 74HC165 shift registers to expand number of GPOIs, running on 5v DC. This will be controlled by an STM32 (STM32F103R8T6), running on 3.3v DC, connected over SPI bus. I read in STM32 datasheet that the GPIOs are 5v tolerant.
I was wondering, if I can have different voltages across these GPIO expansion chips and the μCU. Or is there anything I need to take care of?
I saw similar questions, but in my case, the STM32 seems to be 5v tolerant: