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Philips Semiconductors
Product data
P87C51RA2/RB2/RC2/RD2
80C51 8-bit microcontroller family 8KB/16KB/32KB/64KB OTP
with 512B/1KB RAM, low voltage (2.7 to 5.5 V), low power, high
speed (30/33 MHz)
2003 Jan 24
31
PX0
IP (0B8H)
Priority Bit = 1 assigns high priority
Priority Bit = 0 assigns low priority
BIT
SYMBOL
FUNCTION
IP.7
–
IP.6
PPC
PCA interrupt priority bit
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.
SU01291
PT0
PX1
PT1
PS
PT2
PPC
–
0
1
2
3
4
5
6
7
Figure 16. IP Registers
PX0H
IPH (B7H)
Priority Bit = 1 assigns higher priority
Priority Bit = 0 assigns lower priority
BIT
SYMBOL
FUNCTION
IPH.7
–
IPH.6
PPCH
PCA interrupt priority bit
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.
SU01292
PT0H
PX1H
PT1H
PSH
PT2H
PPCH
–
0
1
2
3
4
5
6
7
Figure 17. IPH Registers