C509-L_97 Datasheet, PDF (203/290 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Interrupt System
C509-L
The SFR IEN1 includes the enable bits for the external interrupts 2 to 6, for the AD converter
interrupt, and for the timer 2 external reload interrupt.
Special Function Register IEN1 (Address B8H)
Reset Value : 00H
MSB
Bit No. BF_H
BE_H
B8H EXEN2 SWDT
BD_H
EX6
BC_H BB_H BA_H
EX5 EX4 EX3
LSB
B9_H B8_H
EX2 EADC
IEN1
Bit
EXEN2
EX6
EX5
EX4
EX3
EX2
EADC
The shaded bit is not used for interrupt control
Function
Timer 2 external reload interrupt enable
If EXEN2 = 0, the timer 2 external reload interrupt is disabled.
The external reload function is not affected by EXEN2.
External interrupt 6 / capture/compare interrupt 3 enable
If EX6 = 0, external interrupt 6 is disabled.
External interrupt 5 / capture/compare interrupt 2 enable
If EX5 = 0, external interrupt 5 is disabled.
External interrupt 4 / capture/compare interrupt 1 enable
If EX4 = 0, external interrupt 4 is disabled.
External interrupt 3 / capture/compare interrupt 0 enable
If EX3 = 0, external interrupt 3 is disabled.
External interrupt 2 / capture/compare interrupt 4 enable
If EX2 = 0, external interrupt 2 is disabled.
Timer 2 external reload interrupt enable
If EADC = 0, the A/D converter interrupt is disabled
Semiconductor Group
7-7
1997-10-01