Datasheet

Section 13 Timer Z
Rev. 3.00 Sep. 10, 2007 Page 233 of 528
REJ09B0216-0300
13.4.4 Synchronous Operation
In synchronous operation, the values in a number of TCNT counters can be rewritten
simultaneously (synchronous presetting). Also, a number of TCNT counters can be cleared
simultaneously by making the appropriate setting in TCR (synchronous clearing). Synchronous
operation enables GR to be increased with respect to a single time base.
Figure 13.19 shows an example of the synchronous operation setting procedure.
No
Yes
Synchronous operation
selection
Clearing
source generation
channel?
Set synchronous
operation
Select counter
clearing source
Synchronous presetting
Set TCNT
Synchronous clearing
[1]
[2]
[3]
Select counter
clearing source
[4]
Start counter operation
[5]
Start counter operation
[5]
[1] Set the SYNC bits in TMDR to 1.
[2] When a value is written to either of the TCNT counters, the same value is simultaneously written to the
other TCNT counter.
[3] Set bits CCLR1 and CCLR0 in TCR to specify counter clearing by compare match/input capture.
[4] Set bits CCLR1 and CCLR0 in TCR to designate synchronous clearing for the counter clearing source.
[5] Set the STR bit in TSTR to 1 to start the count operation.
<Synchronous presetting> <Synchronous clearing><Counter clearing>
Figure 13.19 Example of Synchronous Operation Setting Procedure