A little look at RP2040’s programmable i-o state-machines Raspberry Pi’s microcontroller, the RP2040, has some unusual features. And one of these is the i-o state machine, of which there are eight. spread over two ‘PIO blocks’ – (one shown right). According to the RP2040 data sheet, the four state machines simultaneously execute programs from a shared instruction memory. FIFO data queues buffer data transferred between PIO and the system. GPIO mapping logic allows each state machine to observe and manipulate up to 30 GPIOs. They can be used to implement simple serial bust standards and other functions incliding a VGA video interface – I am now wondering if these state-machines could be used to add some anti-shoot-through timing for the PWM outputs – a need I was pondering in January