TIMERS
The 4250 Group has the programmable timer.
• Programmable timer
The programmable timer has a reload register and enables
the frequency dividing ratio to be set. It is decremented from a
setting value n. When it underflows (count to n + 1), a timer
interrupt request flag is set to “1,” new data is loaded from the
reload register, and count continues (auto-reload function).
MITSUBISHI MICROCOMPUTERS
4250 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
FF16
n : Counter initial value
Count starts
Reload
n
1st underflow
Reload
2nd underflow
0016
Timer 1 interrupt
request flag
n+1 count
Fig. 18 Auto-reload function
n+1 count
Time
An interrupt occurs or
a skip instruction is executed.
MITSUBISHI
20
ELECTRIC