R01UH0823EJ0100 Rev.1.00
Page 683 of 1823
Jul 31, 2019
RX23W Group
25. 16-Bit Timer Pulse Unit (TPUa)
25.3
Operation
25.3.1
Basic Functions
Each channel has a TPUm.TCNT and a TPUm.TGRy register (y = A to D).
TCNT is a 16-bit up-counter, which can function as a free-running counter, periodic counter, or event counter.
TGRy can be used as an input capture register or output compare register.
(1) Counter Operation
When the CSTj bit (j = 0 to 5) in TPU.TSTR is set to 1, the TCNT for the corresponding channel starts counting.
(a) Example of count operation setting procedure
shows an example of the count operation setting procedure.
Figure 25.2
Example of Counter Operation Setting Procedure
Operation selection
Periodic counter
Free-run counter
Select counter clearing source
Select count clock
Set period
Start count
Start count
Select output compare register
<Periodic counter>
<Free-running counter>
[1]
[2]
[3]
[4]
[5]
[5]
[1] Select the count clock with the
TPSC[2:0] bits in TCR. At the same
time, select the input clock edge with
the CKEG[1:0] bits in TCR.
[2] For periodic counter operation, select
the TGRy register to be used as the
TCNT clearing source with the
CCLR[2:0] bits in TCR.
[3] Set the TGRy register selected in [2] as
an output compare register with TIOR
(y = A to D).
[4] Set the periodic counter cycle in the
TGRy register selected in [2].
[5] Set the TPU.TSTR.CSTj bit (j = 0 to 5)
to 1 to start the counter operation.