C509-L_97 Datasheet, PDF (212/290 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Interrupt System
C509-L
The compare timer interrupt is generated by bit CTF in register CTCON, which is set by a rollover
in the compare timer. lf a compare timer interrupt is generated, flag CTF can be cleared by software.
The compare timer 1 interrupt is generated by bit CT1F in register CT1CON, which is set by a
rollover in the compare timer. lf a compare timer interrupt is generated, flag CT1F can be cleared
by software.
The timer 2 compare match set and compare match clear interrupt is generated by bits ICS
and ICR in register CTCON. These flags are set by a match in registers COMSET and COMCLR,
when enabled. As long as the match condition is valid the request flags can't be reset (neither by
hardware nor software).
Special Function Register CTCON (Address. E1H)
Special Function Register CT1CON (Address BCH)
Reset Value : 01000000B
Reset Value : X1XX0000B
MSB
LSB
Bit No. 7
6
5
4
3
2
1
0
E1H T2PS1 CTP ICR ICS CTF CLK2 CLK1 CLK0 CTCON
BCH
7
6
5
– CT1P –
4
3
2
1
0
– CT1F CLK12 CLK11 CLK10 CT1CON
Bit
ICR
ICS
CTF
CT1F
The shaded bits are not used for interrupt purposes.
Function
Interrupt request flag for compare register COMCLR
ICR is set when a compare match occured. ICR is cleared ba hardware when the
processor vectors to interrupt routine.
Interrupt request flag for compare register COMSET
ICS is set when a compare match occured. ICS is cleared by hardware when the
processor vectors to interrupt routine.
Compare timer overflow flag
CTF is set when the compare timer 1 count rolls over from all ones to the reload
value. When CTF is set, a compare timer interrupt can be generated (if enabled).
CTF is cleared by hardware when the compare timer value is no more equal to the
reload value.
Compare timer 1 overflow flag
CT1F is set when the compare timer 1 count rolls over from all ones to the reload
value. When CT1F is set, a compare timer 1 interrupt can be generated (if enabled).
CT1F is cleared by hardware when the compare timer 1 value is no more equal its
reload value.
Semiconductor Group
7-16
1997-10-01