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Interrupt system – Rainbow Electronics T89C51AC2 User Manual

Page 86

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86

T89C51AC2

Rev. B – 19-Dec-01

17. Interrupt System

The controller has a total of 8 interrupt vectors: two external interrupts (INT0 and INT1),
three timer interrupts (timers 0, 1 and 2), a serial port interrupt, a PCA, a timer overrun
interrupt and an ADC. These interrupts are shown below.

Figure 40. Interrupt Control System

EX0

IEN0.0

00

01

10

11

External

Interrupt 0

INT0#

EX1

IEN0.2

External

Interrupt 1

INT1#

ET0

IEN0.1

Timer 0

EC

IEN0.6

PCA

ET1

IEN0.3

Timer 1

ES

IEN0.4

UART

EADC

IEN1.1

A to D

Converter

Interrupt Enable

Lowest Priority Interrupts

Highest

Priority Enable

00

01

10

11

00

01

10

11

00

01

10

11

00

01

10

11

00

01

10

11

00

01

10

11

Priority

Interrupts

AIN1:0

Timer 2

00

01

10

11

ET2

IEN0.5

TxD

RxD

CEX0:5