SIC63616-(Rev. 1.0) NO. P90
3240-0412
4.8.7 Interrupt function
10 Hz and 1 Hz interrupts
The 10 Hz and 1 Hz interrupts can be generated through the overflow of stopwatch timers SWD4–7
and SWD8–11 respectively. Also, software can set whether to separately mask the frequencies described
earlier.
Figure 4.8.7.1 is the timing chart for the counters.
10 Hz interrupt request
1 Hz interrupt request
FF4DH
(1/10 sec BCD)
FF4CH
(1/100 sec BCD)
D0
D1
D2
D3
D0
D1
D2
D3
Address
Register
Stopwatch timer (SWD0–3) timing chart
FF4BH
(1/1,000 sec BCD)
D0
D1
D2
D3
Address
Register
Stopwatch timer (SWD4–7) timing chart
Address
Register
Stopwatch timer (SWD8–11) timing chart
Fig. 4.8.7.1 Timing chart for counters
As shown in Figure 4.8.7.1, the interrupts are generated by the overflow of their respective counters ("9"
changing to "0"). Also, at this time the corresponding interrupt factor flag (ISW10, ISW1) is set to "1".
The respective interrupts can be masked separately through the interrupt mask registers (EISW10,
EISW1). However, regardless of the setting of the interrupt mask registers, the interrupt factor flags are
set to "1" by the overflow of their corresponding counters.