at89s8253-24psu ATMEL Corporation, at89s8253-24psu Datasheet - Page 31

• Manufacturer Part Number: at89s8253-24psu
• Description: At89s8253 8-bit Microcontroller With 12k Bytes Flash And 2k Bytes Eeprom
• Manufacturer: ATMEL Corporation

Table 15-1.
3286K–MICRO–12/06
Interrupt
System Reset
External Interrupt 0
Timer 0 Overflow
External Interrupt 1
Timer 1 Overflow
Serial Port
IE Address = A8H
Bit Addressable
Symbol
EA
–
ET2
ES
ET1
EX1
ET0
EX0
User software should never write 1s to reserved bits, because they may be used in future AT89 products.
Enable Bit = 1 enables the interrupt.
Enable Bit = 0 disables the interrupt.
Position
IE.7
IE.6
IE.5
IE.4
IE.3
IE.2
IE.1
IE.0
EA
Interrupt Enable (IE) Register
Function
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.
Reserved.
Timer 2 interrupt enable bit.
SPI and UART interrupt enable bit.
Timer 1 interrupt enable bit.
External interrupt 1 enable bit.
Timer 0 interrupt enable bit.
External interrupt 0 enable bit.
–
The Timer 0 and Timer 1 flags, TF0 and TF1, are set at S5P2 of the cycle in which the timers
overflow. The values are then polled by the circuitry in the next cycle. However, the Timer 2 flag,
TF2, is set at S2P2 and is polled in the same cycle in which the timer overflows.
ET2
Source
RST or POR or BOD
IE0
TF0
IE1
TF1
RI or TI or SPIF
ES
ET1
EX1
Reset Value = 0X00 0000B
ET0
Vector Address
0000H
0003H
000BH
0013H
001BH
0023H
AT89S8253
EX0
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