Operation; Basic Functions - Renesas H8SX/1650 Hardware Manual

Section 9 16-Bit Timer Pulse Unit (TPU)
9.4

Operation

9.4.1

Basic Functions

Each channel has a TCNT and TGR register. TCNT performs up-counting, and is also capable of
free-running operation, periodic counting, and external event counting.
Each TGR can be used as an input capture register or output compare register.
(1)
Counter Operation
When one of bits CST0 to CST5 is set to 1 in TSTR, the TCNT counter for the corresponding
channel starts counting. TCNT can operate as a free-running counter, periodic counter, and so on.
(a)
Example of count operation setting procedure
Figure 9.2 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
Start count
<Periodic counter>
Figure 9.2 Example of Counter Operation Setting Procedure
Rev.2.00 Jun. 28, 2007 Page 346 of 666
REJ09B0311-0200
[1]
Free-running counter
[2]
[3]
[4]
[5] Start count
<Free-running counter>
[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.
[5]