C511_1 Datasheet, PDF (92/128 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Interrupt System
7.2.2 Interrupt Priorities
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 Registers IP (Address B8H)
Reset Value : X0000000B
MSB
LSB
Bit No. 7
6
5
4
3
2
1
0
B8H
– PSSC PT2 PS PT1 PX1 PT0 PX0 IP
Bit
–
PSSC
PT2
PS
PT1
PX1
PT0
PX0
Function
Not implemented, reserved for future use. Will be read as “1“.
SSC Priority Level
If PSSC = 0, the SSC interrupt has a low priority.
Timer 2 Interrupt Priority Level.
If PT2 = 0, the timer 2 interrupt has a low priority.
Serial Channel (USART) Interrupt Priority Level
(C513//C513A/C513A-H only)
If PS = 0, the serial channel interrupt has a low priority.
Timer 1 Overflow Interrupt Priority Level.
If PT1 = 0, the timer 1 interrupt has a low priority.
External Interrupt 1 Priority Level.
If PX1 = 0, the external interrupt 1 has a low priority.
Timer 0 Overflow Interrupt Priority Level.
If PT0 = 0, the timer 0 interrupt has a low priority.
External Interrupt 0 Priority Level.
If PX0 = 0, the external interrupt 0 has a low priority.
Semiconductor Group
7-5