Synchronous Operation; Figure 12.14 Example Of Synchronous Operation Setting Procedure - Renesas H8S Series Hardware Manual

12.5.2

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 TGR to be incremented with respect to a single time base. Channels 0 to 2 can
all be designated for synchronous operation.
(1) Example of Synchronous Operation Setting Procedure
Figure 12.14 shows an example of the synchronous operation setting procedure.
Synchronous operation
selection
Set synchronous
operation
Synchronous presetting
Set TCNT
<Synchronous presetting>
[1] Set to 1 the SYNC bits in TSYR corresponding to the channels to be designated for synchronous
operation.
[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 to 1 the CST bits in TSTR for the relevant channels, to start the count operation.

Figure 12.14 Example of Synchronous Operation Setting Procedure

[1]
Synchronous clearing
[2]
Clearing
source generation
channel?
Yes
Select counter
clearing source
Start count
<Counter clearing>
Section 12 16-Bit Timer Pulse Unit (TPU)
No
Set synchronous
[3]
counter clearing
[5] Start count
<Synchronous clearing>
Rev. 3.00 Jul. 14, 2005 Page 341 of 986
[4]
[5]
REJ09B0098-0300