Timers; Fig. 18 Auto-Reload Function - Renesas 4513 User Manual

TIMERS

The 4513/4514 Group has the programmable timers.
• 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 re-
quest flag is set to "1," new data is loaded from the reload
register, and count continues (auto-reload function).
FF
16
n : Counter initial value
n
00
16
"1"
Timer interrupt
"0"
request flag

Fig. 18 Auto-reload function

Count starts
1st underflow
n+1 count
4513/4514 Group User's Manual
FUNCTION BLOCK OPERATIONS
• Fixed dividing frequency timer
The fixed dividing frequency timer has the fixed frequency divid-
ing ratio (n). An interrupt request flag is set to "1" after every n
count of a count pulse.
Reload
2nd underflow
n+1 count
An interrupt occurs or
a skip instruction is executed.
HARDWARE
Reload
Time
1-29