Notably, the XMOS xcore.ai series of chips have no dedicated hardware peripherals - their 100BASE-TX MAC (as well as UART, SPI, I2C, I2S etc) is entirely softwa

Notably, the XMOS xcore.ai series of chips have no dedicated hardware peripherals - their 100BASE-TX MAC (as well as UART, SPI, I2C, I2S etc) is entirely software defined. A very different approach to most other microcontrollers: https://github.com/xmos/lib_ethernet https://github.com/xmos/lib_ethernet