Interrupt System - Siemens C541U User Manual

7

Interrupt System

The C541U provides seven interrupt sources with two priority levels. Five interrupts can be
generated by the on-chip peripherals (timer 0, timer 1, SSC interface, and USB module), and two
interrupts may be triggered externally (P3.2/INT0 and P3.3/INT1).
Figure 7-1 and 7-2 give a general overview of the interrupt sources and illustrate the request and
control flags which are described in the next sections.
Timer 0
Overflow
Timer 1
Overflow
P3.2 /
INT0
IT0
TCON.0
P3.3 /
INT1
IT1
TCON.2
Bit addressable
Request flag is cleared by hardware
Figure 7-1
Interrupt Request Sources (Part 1)
Semiconductor Group
TF0
TCON.5
TF1
TCON.7
>1
IE0
TCON.1
ITCON.0
ITCON.1
>1
IE0
TCON.3
ITCON.2
ITCON.3
000B
H
ET0
IEN0.1
001B
H
ET1
IEN0.3
0003
H
EX0
IEN0.0
0013
H
EX1
IEN0.2
EA
IEN0.7
7-1
Interrupt System
C541U
Low Priority
High Priority
PT0
IP0.1
PT1
IP0.3
PX0
IP0.0
PX1
IP0.2
MCT03684
1997-10-01