P8XC592 Datasheet, PDF (63/108 Pages) NXP Semiconductors – 8-bit microcontroller with on-chip CAN

Philips Semiconductors
8-bit microcontroller with on-chip CAN
14 INTERRUPT SYSTEM
External events and the real-time-driven on-chip
peripherals require service by the CPU asynchronous to
the execution of any particular section of code. To tie the
asynchronous activities of these functions to normal
program execution a multiple-source, two-priority-level,
nested interrupt system is provided. Interrupt response
latency is from 2.25 µs to 7.5 µs when using a 16 MHz
crystal. The latency time strongly depends on the
sequence of instructions executed directly after an
interrupt request. During a CAN-DMA transfer the interrupt
system is disabled (see Section 13.5.17). The P8xC592
acknowledges interrupt requests from fifteen sources as
follows:
• INT0 and INT1: externally via pins 27 and 28
respectively
• Timer 0 and Timer 1: from the two internal counters
– If the capture function remains unused and the
Capture Register contents are ‘don't care’ then the
corresponding input pins ‘CTnI’, with ‘n = 0 ... 3’, may
be used as positive and/or negative edge triggered
external interrupts INT2 to INT5. But note that they
can not terminate the Idle mode because the Timer 2
is switched off then
• Timer T2, 8 separate interrupts:
– 4 capture interrupts
– 3 compare interrupts
– an overflow interrupt
• ADC end-of-conversion interrupt
• CAN-controller interrupt
• UART serial I/O port interrupt.
Each interrupt vectors to a separate location in Program
Memory for its service program. Each source can be
individually enabled or disabled by a corresponding bit in
the IEN0 or IEN1 register, moreover each interrupt may be
programmed to a HIGH or LOW priority level using a
corresponding bit in the IP0 or IP1 register. Also all
enabled sources can be globally disabled or enabled. Both
external interrupts can be programmed to be
level-activated or transition-activated, and an active LOW
level allows ‘wire-ORing’ of several interrupt sources to the
input pin.
1996 Jun 27
63
Product specification
P8xC592