AT89S4051 Atmel Corporation, AT89S4051 Datasheet - Page 13

• Manufacturer Part Number: AT89S4051
• Manufacturer: Atmel Corporation

Specifications of AT89S4051

• Flash (kbytes): 4 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 15
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 2
• Isp: SPI

14. Interrupt Registers
Table 14-1.
Table 14-2.
Table 14-3.
3390E–MICRO–6/08
Symbol
EA
EC
ES
ET1
EX1
ET0
EX0
Symbol
PC
PS
PT1
PX1
PT0
PX0
Symbol
PCH
PSH
PT1H
PX1H
PT0H
PX0H
IE = A8H
Bit Addressable
Bit
IP = B8H
Bit Addressable
Bit
IPH = B7H
Not Bit Addressable
Bit
Function
Global enable/disable. All interrupts are disabled when EA = 0. When EA = 1, each interrupt source is enabled/disabled
by setting/clearing its own enable bit.
Comparator Interrupt Enable
Serial Port Interrupt Enable
Timer 1 Interrupt Enable
External Interrupt 1 Enable
Timer 0 Interrupt Enable
External Interrupt 0 Enable
Function
Comparator Interrupt Priority Low
Serial Port Interrupt Priority Low
Timer 1 Interrupt Priority Low
External Interrupt 1 Priority Low
Timer 0 Interrupt Priority Low
External Interrupt 0 Priority Low
Function
Comparator Interrupt Priority High
Serial Port Interrupt Priority High
Timer 1 Interrupt Priority High
External Interrupt 1 Priority High
Timer 0 Interrupt Priority High
External Interrupt 0 Priority High
IE
IP
IPH
– Interrupt Enable Register
– Interrupt Priority Register
EA
7
–
7
–
7
– Interrupt Priority High Register
.
.
PCH
EC
PC
6
6
6
–
5
–
5
–
5
PSH
ES
PS
4
4
4
PT1H
ET1
PT1
3
3
3
PX1H
EX1
PX1
2
2
2
AT89S2051/S4051
Reset Value = X0X0 0000B
Reset Value = X0X0 0000B
Reset Value = 00X0 0000B
PT0H
ET0
PT0
1
1
1
PX0H
EX0
PX0
0
0
0
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