HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 395

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Caution on Period Setting
When counter clearing by compare match is set, TCNT is cleared in the final state in which it
matches the TGR value (the point at which the count value matched by TCNT is updated).
Consequently, the actual counter frequency is given by the following formula:
Where f: Counter frequency
Contention between TCNT Write and Clear Operations
If the counter clear signal is generated in the T2 state of a TCNT write cycle, TCNT clearing takes
precedence and the TCNT write is not performed.
Figure 9.45 shows the timing in this case.
Address
Write signal
Counter clear
signal
TCNT
N: TGR set value
f =
: Operating frequency
Figure 9.45 Contention between TCNT Write and Clear Operations
(N + 1)
N
TCNT write cycle
TCNT address
T1
T2
Rev.3.00 Mar. 26, 2007 Page 353 of 772
Section 9 16-Bit Timer Pulse Unit (TPU)
H'0000
REJ09B0355-0300