S3F80P5_UM_ REV1.00 TIMER 2
TIMER 2 MATCH INTERRUPT
Timer 2 can also be used to generate a match interrupt (IRQ3, vector F2H) whenever the 16-bit counter value
matches the value that is written to the timer 2 reference data registers, T2DATAH and T2DATAL. When a match
condition is detected by the 16-bit comparator, the match interrupt is generated, the counter value is cleared, and
up counting resumes from ‘00H’.
In match mode, program software can poll the timer 2 match/capture interrupt pending bit, T2CON.0, to detect
when a timer 2 match interrupt pending condition exists (T2CON.0 = “1”). When the interrupt request is
acknowledged by the CPU and the service routine starts, the interrupt service routine for vector F2H must clear
the interrupt pending condition by writing a “0” to T2CON.0.
Match CTL
T2CON.5
T2CON.4
P3.0
R (Clear)
Pending
(T2CO N.0)
Interrupt
Enable/Disable
(T2CO N.1)
16-Bit Up Counter
CLK
16-Bit Comparator
Timer 2 High/Low
Buffer R egis te r
Timer 2 Data High/Low
Buffer R egis te r
IRQ3 (T 2INT )
Match Signal
T2CON.3
Figure 13-2. Simplified Timer 2 Function Diagram: Interval Timer Mode
13-3