HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 443

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

11.5
11.5.1
If a timer counter clock pulse is generated during the T2 state of a TCNT write cycle, the write
takes priority and the timer counter is not incremented. Figure 11.8 shows this operation.
11.5.2
If bits CKS2 to CKS0 in TCSR are written to while the WDT is operating, errors could occur in
the incrementation. Software must stop the watchdog timer (by clearing the TME bit to 0) before
changing the value of bits CKS2 to CKS0.
Usage Notes
Contention between Timer Counter (TCNT) Write and Increment
Changing Value of CKS2 to CKS0
Address
Internal write signal
TCNT input clock
pulse
TCNT
Figure 11.8 Contention between TCNT Write and Increment
TCNT write cycle
T1
N
T2
Rev.3.00 Mar. 26, 2007 Page 401 of 772
Counter write data
Section 11 Watchdog Timer
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REJ09B0355-0300