User’s Manual
7-10
05.99
Interrupt System
C513AO
7.2.3 Interrupt Priority Registers
Each interrupt source can also be individually programmed to one of two priority levels by setting
or clearing a bit in the SFR IP (Interrupt Priority: 0 = low priority, 1 = high priority).
Special Function Register IP (Address B8H)
Reset Value: X0000000B
Bit
Function
–
Reserved for future use.
PSSC
SSC Priority Level
If PSSC = 0, the SSC interrupt has a low priority.
PT2
Timer 2 interrupt priority level
If PT2 = 0, the Timer 2 interrupt has a low priority.
PS
USART Serial Channel Interrupt Enable
If PS = 0, the Serial Channel interrupt has a low priority.
PT1
Timer 1 Overflow Interrupt Priority Level
If PT1 = 0, the Timer 1 interrupt has a low priority.
PX1
External interrupt 1 priority level
If PX1 = 0, the external interrupt 1 has a low priority.
PT0
Timer 0 Overflow Interrupt Priority Level
If PT0 = 0, the Timer 0 interrupt has a low priority.
PX0
External interrupt 0 priority level
If PX0 = 0, the external interrupt 0 has a low priority.
MSB
LSB
IP
–
PSSC
PT2
PS
PT1
PX1
PT0
PX0
7
6
5
4
3
2
1
0
Bit No.
B8H
