My sweet summer child… this is backwards compatibility to the I/O register set of NatSemi/Intel's 8250 UART chip… …from 1978. https://en.m.wikipedia.org/wiki/

My sweet summer child… this is backwards compatibility to the I/O register set of NatSemi/Intel's 8250 UART chip… …from 1978. https://en.m.wikipedia.org/wiki/8250_UART https://en.m.wikipedia.org/wiki/8250_UART The definitions are correct, look up an 16550 datasheet if you want to lose some sanity :)