User`s manual

Semiconductor Group 7-6
Interrupt System
C501
7.1.3 Interrupt Priority Register
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 B8
H
) Reset Value : XX000000
B
The shaded bits are not used for interrupt control.
Bit Function
– Not implemented. Reserved for future use.
PT2 Timer 2 Interrupt Priority Level.
If PT2 = 0, the Timer 2 interrupt has a low priority.
PS Serial Channel Interrupt Priority Level.
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
– – PT2 PS
B8
H
IP
PT1 PX1 PT0 PX0
Bit No.76543210