Section 13 Timer Z
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.
Synchronous operation
selection
Set synchronous
[1]
operation
Synchronous presetting
Set TCNT
Synchronous clearing
Clearing
source generation
channel?
No
[2]
Yes
Select counter
clearing source
Select counter
clearing source
[3]
[5]
[4]
[5]
Start counter operation
Start counter operation
<Synchronous clearing>
<Synchronous presetting>
<Counter clearing>
[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.
Figure 13.19 Example of Synchronous Operation Setting Procedure
Rev. 3.00 Sep. 10, 2007 Page 233 of 528
REJ09B0216-0300
RENESAS [ RENESAS TECHNOLOGY CORP ]
