RX610 Group
17. 8-Bit Timer (TMR)
R01UH0032EJ0120 Rev.1.20
Page 582 of 1006
Feb 20, 2013
17.7
Usage Notes
17.7.1
Module Stop State Setting
Operation of the TMR can be disabled or enabled by using the module-stop control registers. The initial setting is for
halting of TMR operation. Register access becomes possible after release from the module-stop state. For details, see
section 8, Power-Down Modes.
17.7.2
Notes on Setting Cycle
If the compare match is selected for counter clear, TCNT is cleared at the last state in the cycle in which the value of
TCNT matches with that of TCORA or TCORB. TCNT updates the counter value at this last state. Therefore, the counter
frequency is obtained by the following formula (f: Counter frequency,
φ
: Operating frequency, N: TCORA and TCORB
register setting value).
f =
φ
/ (N + 1)
17.7.3
Conflict between TCNT Write and Counter Clear
If a counter clear signal is generated concurrently with CPU write to TCNT, the clear takes priority and the write is not
performed as shown in figure 17.13.
Counter clear signal
TCNT
PCLK
TCNT counter write by CPU
00h
N
Figure 17.13 Conflict between TCNT Write and Counter Clear