AT89C55WD-33JC(2002) View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT89C55WD-33JC
(Rev.:2002)

8-bit Microcontroller with 20K Bytes Flash

Atmel Corporation 

Table 7. Interrupt Enable (IE) Register

(MSB)

EA

–

ET2

ES

Enable Bit = 1 enables the interrupt.

Enable Bit = 0 disables the interrupt.

(LSB)

ET1

EX1

ET0

EX0

Symbol

Position

Function

EA

IE.7

Disables all interrupts. If EA = 0, no interrupt is acknowledged. If EA

= 1, each interrupt source is individually enabled or disabled by

setting or clearing its enable bit.

–

IE.6

Reserved.

ET2

IE.5

Timer 2 interrupt enable bit.

ES

IE.4

Serial Port interrupt enable bit.

ET1

IE.3

Timer 1 interrupt enable bit.

EX1

IE.2

External interrupt 1 enable bit.

ET0

IE.1

Timer 0 interrupt enable bit.

EX0

IE.0

External interrupt 0 enable bit.

User software should never write 1s to reserved bits, because they may be used in future AT89

products.

Figure 10. Interrupt Sources

0

INT0

IE0

1

TF0

0

INT1

IE1

1

TF1

TI

RI

TF2

EXF2

18 AT89C55WD

1921B–MICRO–09/02

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