Datasheet

Philips Semiconductors Product data
P80C3xX2; P80C5xX2;
P87C5xX2
80C51 8-bit microcontroller family
4K/8K/16K/32K ROM/OTP, low voltage (2.7 to 5.5 V),
low power, high speed (30/33 MHz)
2003 Jan 24
34
EX0
Enable Bit = 1 enables the interrupt.
Enable Bit = 0 disables it.
BIT SYMBOL FUNCTION
IE.7 EA Global disable bit. If EA = 0, all interrupts are disabled. If EA = 1, each interrupt can be individually
enabled or disabled by setting or clearing its enable bit.
IE.6 — Not implemented. Reserved for future use.
IE.5 ET2 Timer 2 interrupt enable bit.
IE.4 ES Serial Port interrupt enable bit.
IE.3 ET1 Timer 1 interrupt enable bit.
IE.2 EX1 External interrupt 1 enable bit.
IE.1 ET0 Timer 0 interrupt enable bit.
IE.0 EX0 External interrupt 0 enable bit.
SU01522
ET0EX1ET1ESET2—EA
01234567
IE Address = 0A8H
Bit Addressable
Reset Value = 0X000000B
Figure 22. Interrupt Enable (IE) Register
PX0
Priority Bit = 1 assigns higher priority
Priority Bit = 0 assigns lower priority
BIT SYMBOL FUNCTION
IP.7 — Not implemented, reserved for future use.
IP.6 — Not implemented, reserved for future use.
IP.5 PT2 Timer 2 interrupt priority bit.
IP.4 PS Serial Port interrupt priority bit.
IP.3 PT1 Timer 1 interrupt priority bit.
IP.2 PX1 External interrupt 1 priority bit.
IP.1 PT0 Timer 0 interrupt priority bit.
IP.0 PX0 External interrupt 0 priority bit.
SU01523
PT0PX1PT1PSPT2——
01234567
IP Address = 0B8H
Bit Addressable
Reset Value = xx000000B
Figure 23. Interrupt Priority (IP) Register
PX0H
Priority Bit = 1 assigns higher priority
Priority Bit = 0 assigns lower priority
BIT SYMBOL FUNCTION
IPH.7 — Not implemented, reserved for future use.
IPH.6 — Not implemented, reserved for future use.
IPH.5 PT2H Timer 2 interrupt priority bit high.
IPH.4 PSH Serial Port interrupt priority bit high.
IPH.3 PT1H Timer 1 interrupt priority bit high.
IPH.2 PX1H External interrupt 1 priority bit high.
IPH.1 PT0H Timer 0 interrupt priority bit high.
IPH.0 PX0H External interrupt 0 priority bit high.
SU01524
PT0HPX1HPT1HPSHPT2H——
01234567
IPH Address = B7H
Bit Addressable
Reset Value = xx000000B
Figure 24. Interrupt Priority HIGH (IPH) Register