Datasheet

408
12.7.17 Contention between TCNT Write and Overflow/Underflow
If there is an up-count or down-count in the T2 state of a TCNT write cycle, and
overflow/underflow occurs, the TCNT write takes precedence and the TCFV/TCFU flag in TSR is
not set .
Figure 12.94 shows the operation timing in this case.
φ
Address
Write signal
TCNT input
clock
TCNT
TCFV flag
H'FFFF N TCNT write data
Disabled
TCNT write cycle
T1 T2
TCNT address
Figure 12.94 Contention between TCNT Write and Overflow