SH7011 Datasheet, PDF (131/292 Pages) Renesas Technology Corp – CMOS single-chip microprocessors

8.4.3 Synchronous Operation
There are two kinds of synchronous operation, synchronized preset and synchronized clear. The
synchronized preset operation allows multiple timer counters (TCNT) to be rewritten
simultaneously, while the synchronized clear operation allows multiple TCNT counters to be
cleared simultaneously using timer control register (TCR) settings.
The synchronizing mode can increase the number of TGR registers for a single time base. All five
channels can be set for synchronous operation.
Procedure for Selecting the Synchronizing Mode (Figure 8.14):
1. Set 1 in the SYNC bit of the timer synchro register (TSYR) to use the corresponding channel
in the synchronizing mode.
2. When a value is written in the TCNT in any of the synchronized channels, the same value is
simultaneously written in the TCNT in the other channels.
3. Set the counter to clear with output compare/input capture using bits CCLR2–CCLR0 in the
TCR.
4. Set the counter clear source to synchronized clear using the CCLR2–CCLR0 bits of the TCR.
5. Set the CST bits for the corresponding channels in the TSTR to 1 to start counting in the
TCNT.
Select
synchronizing mode
Set synchronizing (1)
mode
Synchronized preset
Synchronized clear
Set TCNT
(2)
Channel that
No
generated clear
source?
Yes
Select counter
(3)
clear source
Start counting
(5)
Set counter
(4)
synchronous clear
Start counting
(5)
Synchronized preset
Counter clear
Synchronized clear
Figure 8.14 Procedure for Selecting Synchronizing Operation
122