SIM and RIM also allow the global interrupt mask state and the three independent RST interrupt mask states to be read, the pending-interrupt states of those same three interrupts to be read, the RST 7.5 trigger-latch flip-flop to be reset ( cancelling the pending interrupt without servicing it ), and serial data to be sent and received via the SOD and SID pins, respectively, all under program control and independently of each other.
