Intel MCS 51 User Manual

i~.
87C51GBHARDWAREDESCRIPTION
Table23.InterruptPriorityRegisters
1P
Address= OB8H
ResetValue= XOOOOOOOB
BitAd&esesble
1
—
PPC I PT2 ] PS
PT1 Pxl PTo Pxo
IPA
Address= OB8H
ResetValue= 0000OOOOB
NotBitAddressable
PADI PX6
PX5 I PX4 PX3 PX2 PCI I PSEP
IPH Address= OB7H
ResetValue= XOOO00006
NotBitAddressable
I
—
PPPC
PT2H PSH PTIH PXIH PTOH PXOH
IPHA
Address= OB5H
ResetValue= 0000OOOOB
NotBitAddressable
PADH PX6H
PX5H PX4H PX3H PX2H PCIH PSEP
PriorityBit
I
PriorityBitH
I
Priority
I
o 0
Lowest
o 1
1 0
1 1
Hiahest
Symbol
Function
—
PPC,PPCH
PT2,PT2H
PS,PSH
PT1,PTIH
PX1,PXIH
PTO,PTOH
PXO,PXOH
PAD,PADH
PX6,PX6H
PX5,PX5H
PX4,PX4H
PX3,PX3H
PX2,PX2H
PCl, PCIH
PSEP,PSEPH
NotImplemented, reserved for future use*
PCA interrupt priority bits
Timer
2 interrupt priority bits
Serial Port interrupt prioritybits
Timer 1 interrupt priority bits
External intermpt 1 interrupt priority bits
Timer Ointenupt priority bits
External interrupt Ointerrupt priority bits
A/Dconverterinterruptprioritybits
Externalinterrupt6 interruptprioritybits
Externalinterrupt
5 interruptprioritybits
Externalinterrupt4interruptprioritybits
Externalinterrupt3 interruptprioritybits
EXtOfrtSlinterrupt2interruptprioritybits
PCAIintermptprioritybits
SerialExpansionPortinterruptprioritybits
NOTE:
‘IJser software should not write Is to resewed bits. These bits may be used in future 8051 family products to invoke
new features. In that case,
theresetorinaotivevalueof the new bit will be O,and h activevalue will be 1. The value
read froma resewed bitis indeterminate.
6-46

Intel MCS 51 Specifications

General

Brand	Intel
Model	MCS 51
Category	Microcontrollers
Language	English