SAF-C502-2R20N Siemens Semiconductor Group, SAF-C502-2R20N Datasheet - Page 27

• Manufacturer Part Number: SAF-C502-2R20N
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: Siemens Semiconductor Group

Table 11
Interrupt Sources and their Corresponding Interrupt Vectors
Source (Request Flags)
IE0
TF0
IE1
TF1
RI + TI
TF2 + EXF2
A low-priority interrupt can itself be interrupted by a high-priority interrupt, but not by another low-
priority interrupt. A high-priority interrupt cannot be interrupted by any other interrupt source.
If two requests of different priority level are received simultaneously, the request of higher priority is
serviced. If requests of the same priority are received simultaneously, an internal polling sequence
determines which request is serviced. Thus within each priority level there is a second priority
structure determined by the polling sequence as shown in table 12.
Table 12
Interrupt Priority-within-Level
External Interrupt 0,
Timer 0 Interrupt,
External Interrupt 1,
Timer 1 Interrupt,
Serial Channel,
Timer 2 Interrupt,
Semiconductor Group
Interrupt Source
IE0
TF0
IE1
TF1
RI or TI
TF2 or EXF2
Vector
External interrupt 0
Timer 0 interrupt
External interrupt 1
Timer 1 interrupt
Serial port interrupt
Timer 2 interrupt
26
Priority
High
Low
0003 H
000B H
0013 H
001B H
0023 H
002B H
Vector Address
C502