Datasheet Summary
CDP1877, CDP1877C
March 1997
Programmable Interrupt Controller (PIC)
Description
The CDP1877 and CDP1877C are programmable 8-level interrupt controllers designed for use in CDP1800 series microprocessor systems. They provide added versatility by extending the number of permissible interrupts from 1 to N in increments of 8. When a high to low transition occurs on any of the PIC interrupt lines (IR0 to IR7), it will be latched and, unless the request is masked, it will cause the INTERRUPT line on the PIC and consequently the INTERRUPT input on the CPU to go low. The CPU accesses the PIC by having interrupt vector register R(1) loaded with the memory address of the PIC. After the interrupt...
