
67
AT89C51ID2
4289C–8051–11/05
Table 51. IPH0 Register
IPH0 - Interrupt Priority High Register (B7h)
Reset Value = X000 0000b
Not bit addressable
76
543
210
-
PPCH
PT2H
PSH
PT1H
PX1H
PT0H
PX0H
Bit
Number
Bit
Mnemonic
Description
7-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
6
PPCH
PCA interrupt Priority high bit.
PPCHPPCLPriority Level
0
0Lowest
01
10
1
1Highest
5PT2H
Timer 2 overflow interrupt Priority High bit
PT2HPT2LPriority Level
0
0Lowest
01
10
1
1Highest
4
PSH
Serial port Priority High bit
PSH PSLPriority Level
0
0Lowest
0
1
0
1
1Highest
3PT1H
Timer 1 overflow interrupt Priority High bit
PT1HPT1L Priority Level
00 Lowest
01
10
11Highest
2
PX1H
External interrupt 1 Priority High bit
PX1HPX1LPriority Level
0
0Lowest
01
10
1
1Highest
1PT0H
Timer 0 overflow interrupt Priority High bit
PT0HPT0LPriority Level
0
0Lowest
0
1
10
1
1Highest
0
PX0H
External interrupt 0 Priority High bit
PX0H PX0LPriority Level
0
0Lowest
01
10
1
1Highest