8259 microprocessor is defined as a Programmable Interrupt Controller (PIC) microprocessor. There are 5 hardware interrupts and 2 hardware interrupts in 8085 and 8086 respectively. But by connecting 8259 with the CPU, we can increase the interrupt handling capability. It combines the multiple interrupt input sources into a single interrupt output. Interfacing of single PIC provides 8 interrupts inputs from IR0-IR7.
For example, Interfacing of 8085 and 8259 increases the interrupt handling capability of it from 5 to 8 interrupt levels.
It can be programmed according to given interrupts conditions and it can be provided either with level or edge-triggered interrupt levels.
It can be programmed to either work in 8085 or in it.
Individual interrupt bits can be masked.
By conducting more than 8259 we can get up to 64 interrupt pins.
Features of 8259 PIC microprocessor
Intel 8259 is designed for Intel 8085 and Intel 8086 microprocessors.
It can be programmed either in level triggered or in edge-triggered interrupt level.
We can mask individual bits of interrupt request register.
We can increase interrupt handling capability up to 64 interrupt levels by cascading further 8259 PIC.
