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Interrupt system, Overview – Rainbow Electronics AT89C5131 User Manual

Page 90

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90

AT89C5131

4136A–USB–03/03

Interrupt System

Overview

The AT89C5131 has a total of 15 interrupt vectors: two external interrupts (INT0 and
INT1), three timer interrupts (timers 0, 1 and 2), the serial port interrupt, SPI interrupt,
Keyboard interrupt, USB interrupt and the PCA global interrupt. These interrupts are
shown in Figure 39.

Figure 39. Interrupt Control System

IE1

0

3

High priority

interrupt

Interrupt

Polling

Sequence, Decreasing From
High-to-Low Priority

Low Priority

Interrupt

Global Disable

Individual Enable

EXF2

TF2

TI

RI

TF0

INT0

INT1

TF1

IPH, IPL

IE0

0

3

0

3

0

3

0

3

0

3

0

3

PCA IT

KBD IT

SPI IT

0

3

0

3

0

3

UEPINT

USBINT

0

3