Z8F6421PM020SC Datasheet, PDF (82/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
62
Interrupt Controller
Overview
The interrupt controller on the 64K Series products prioritizes the interrupt requests from
the on-chip peripherals and the GPIO port pins. The features of the interrupt controller
include the following:
• 24 unique interrupt vectors:
– 12 GPIO port pin interrupt sources
– 12 on-chip peripheral interrupt sources
• Flexible GPIO interrupts
– 8 selectable rising and falling edge GPIO interrupts
– 4 dual-edge interrupts
• 3 levels of individually programmable interrupt priority
• Watch-Dog Timer can be configured to generate an interrupt
Interrupt requests (IRQs) allow peripheral devices to suspend CPU operation in an orderly
manner and force the CPU to start an interrupt service routine (ISR). Usually this interrupt
service routine is involved with the exchange of data, status information, or control infor-
mation between the CPU and the interrupting peripheral. When the service routine is com-
pleted, the CPU returns to the operation from which it was interrupted.
The eZ8 CPU supports both vectored and polled interrupt handling. For polled interrupts,
the interrupt control has no effect on operation. Refer to the eZ8 CPU User Manual for
more information regarding interrupt servicing by the eZ8 CPU. The eZ8 CPU User Man-
ual is available for download at www.zilog.com.
Interrupt Vector Listing
Table 23 lists all of the interrupts available in order of priority. The interrupt vector is
stored with the most significant byte (MSB) at the even Program Memory address and the
least significant byte (LSB) at the following odd Program Memory address.
PS019915-1005
Interrupt Controller