; register addresses
cons_icsr == {8}177560 ; input-side csr
cons_ibuf == {8}177562 ; input-side data buffer
cons_ocsr == {8}177564 ; output-side csr
cons_obuf == {8}177566 ; output-side data buffer
; bits in cons_icsr
cons_icsr_rdy == {8}200 ; character avaiable in cons_ibuf
cons_icsr_ie  == {8}100 ; interrupt when rdy goes from 0 to 1
; bits in cons_ocsr
cons_ocsr_rdy == {8}200 ; cons_obuf is ready to accept a character
cons_ocsr_ie  == {8}100 ; interrupt when rdy goes from 0 to 1
; interrupt vectors
cons_ivec == {8}60 ; when character arrives on input
cons_ovec == {8}64 ; when room for another character on output