Renesas H8SX/1650, Hardware Manual

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Section 9 16-Bit Timer Pulse Unit (TPU)
Rev.2.00 Jun. 28, 2007 Page 352 of 666
REJ09B0311-0200
9.4.2 Synchronous Operation
In synchronous operation, the values in multiple TCNT counters can be rewritten simultaneously
(synchronous presetting). Also, multiple TCNT counters can be cleared simultaneously
(synchronous clearing) by making the appropriate setting in TCR.
Synchronous operation enables TGR to be incremented with respect to a single time base.
Channels 0 to 5 can all be designated for synchronous operation.
(1)
Example of Synchronous Operation Setting Procedure
Figure 9.10 shows an example of the synchronous operation setting procedure.
Synchronous operation
selection
Set TCNT
Synchronous presetting
<Synchronous presetting>
[1]
[2]
Synchronous clearing
Select counter
clearing source
<Counter clearing>
[3]
Start count [5]
Set synchronous
counter clearing
<Synchronous clearing>
[4]
Start count [5]
Clearing
source generation
channel?
No
Yes
[1] Set the SYNC bits in TSYR corresponding to the channels to be designated for synchronous operation to 1.
[2] When the TCNT counter of any of the channels designated for synchronous operation is written to, the
same value is simultaneously written to the other TCNT counters.
[3] Use bits CCLR2 to CCLR0 in TCR to specify TCNT clearing by input capture/output compare, etc.
[4] Use bits CCLR2 to CCLR0 in TCR to designate synchronous clearing for the counter clearing source.
[5] Set the CST bits in TSTR for the relevant channels to 1, to start the count operation.
Set synchronous
operation
Figure 9.10 Example of Synchronous Operation Setting Procedure