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Section 11 Multi-Function Timer Pulse Unit 2
R01UH0134EJ0400 Rev. 4.00 Page 507 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
11.4 Operation
11.4.1 Basic Functions
Each channel has a TCNT and TGR register. TCNT performs up-counting, and is also capable of
free-running operation, cycle counting, and external event counting.
Each TGR can be used as an input capture register or output compare register.
Always select functions for external pins of this module using the general I/O ports.
(1) Counter Operation
When one of bits CST0 to CST4 in TSTR is set to 1, the TCNT counter for the corresponding
channel begins counting. TCNT can operate as a free-running counter, periodic counter, for
example.
(a) Example of Count Operation Setting Procedure
Figure 11.4 shows an example of the count operation setting procedure.
Operation selection
Select counter clock
Periodic counter
Select counter clearing
source
Select output compare
register
Set period
Free-running counter
Start count operation
<Free-running counter>
<Periodic counter>
Start count operation
[1]
[2]
[3]
[4]
[5]
[5]
[1] Select the counter clock
with bits TPSC2 to TPSC0
in TCR. At the same time,
select the input clock edge
with bits CKEG1 and
CKEG0 in TCR.
[2] For periodic counter
operation, select the TGR
to be used as the TCNT
clearing source with bits
CCLR2 to CCLR0 in TCR.
[3] Designate the TGR
selected in [2] as an output
compare register by means
of TIOR.
[4] Set the periodic counter
cycle in the TGR selected
in [2].
[5] Set the CST bit in TSTR to
1 to start the counter
operation.
Figure 11.4 Example of Counter Operation Setting Procedure