R01UH0823EJ0100 Rev.1.00
Page 661 of 1823
Jul 31, 2019
RX23W Group
25. 16-Bit Timer Pulse Unit (TPUa)
25.2
Register Descriptions
25.2.1
Timer Control Register (TCR)
Note 1. Bit 7 is reserved in TPU1, TPU2, TPU4, and TPU5. These bits are read as 0. The write value should be 0.
TPUm.TCR settings should be made while TPUm.TCNT operation is stopped.
TPSC[2:0] Bits (Timer Prescaler Select)
These bits select the TCNT clock. The clock source can be selected independently for each channel.
To select the external clock as the clock source, set the bit in the port direction register (PDR) for the corresponding pin
to 0 (input port), and set the bit in the port mode register (PMR) to 1 (uses the pin as an I/O port for peripheral functions).
For details, see
.
CKEG[1:0] Bits (Input Clock Edge Select)
These bits select the input clock edge.
When the internal clock is counted using both edges, the input clock period is halved (e.g. Both edges of PCLK/4 =
PCLK/2 rising edge).
Internal clock edge selection is valid when the input clock is PCLK/4 or slower. This setting is ignored if the input clock
is PCLK/1, or when overflow/underflow of another channel is selected.
Address(es): TPU0.TCR 0008 8110h, TPU1.TCR 0008 8120h, TPU2.TCR 0008 8130h,
TPU3.TCR 0008 8140h, TPU4.TCR 0008 8150h, TPU5.TCR 0008 8160h
b7
b6
b5
b4
b3
b2
b1
b0
CCLR[2:0]
CKEG[1:0]
TPSC[2:0]
Value after reset:
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b2 to b0
Timer Prescaler Select
R/W
b4, b3
Input Clock Edge Select
R/W
b7 to b5
Counter Clear Source Select*
See Table 25.11 and Table 25.12.
R/W