Datasheet

Section 12 Timer Z
Rev. 2.00 Sep. 23, 2005 Page 175 of 444
REJ09B0068-0200
12.4 Operation
12.4.1 Counter Operation
When one of bits STR0 and STR1 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. Figure 12.7 shows an example of the counter operation setting procedure.
[1] Select the counter
clock with bits
TPSC2 to TPSC0 in
TCR. When an external clock
is selected, select the external
clock edge with bits CKEG1
and CKEG0 in TCR.
[2] For periodic counter
operation, select the TCNT
clearing source with bits
CCLR2 to CCLR0 in TCR.
[3] Designate the general
register selected in [2] as an
output compare register by
means of TIOR.
[4] Set the periodic counter
cycle in the general register
selected in [2].
[5] Set the STR bit in TSTR
to 1 to start the counter
operation.
Operation selection
Periodic counter Free-running counter
[1]
Select counter clock
[2]
Select counter clearing source
[3]
Select output compare register
[5]
Start count operation
[4]Set period
Figure 12.7 Example of Counter Operation Setting Procedure