
P89V52X2_3
NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 — 4 May 2009
31 of 57
NXP Semiconductors
P89V52X2
80C51 with 256 B RAM, 192 B data EEPROM
Fig 19. Interrupt structure
002aac568
highest
priority
interrupt
polling
sequence
INT0#
IE and IEA
registers
IP/IPH/IPA/IPAH
registers
individual
enables
global
disable
IE0
0
1
IT0
lowest
priority
interrupt
TF0
INT1#
TF1
RI
TI
TF2
EXF2
IE1
0
1
IT1
Table 25.
IE - Interrupt enable register (address A8H) bit allocation
Bit addressable; Reset value: 00H
Bit
7
6
5
4
3
2
1
0
Symbol
EA
-
ET2
ES
ET1
EX1
ET0
EX0
Table 26.
IE - Interrupt enable register (address A8H) bit description
Bit
Symbol
Description
7
EA
Interrupt Enable Bit: EA = 1 interrupt(s) can be serviced, EA = 0
interrupt servicing disabled.
6
-
Reserved
5
ET2
Timer 2 Overow Interrupt Enable
4
ES
Serial Port Interrupt Enable
3
ET1
Timer 1 Overow Interrupt Enable.