Renesas F-ZTAT H8 Series Hardware Manual page 455

Bit 6—Timer Mode Select (WT/IT IT IT IT): Selects whether to use the WDT as a watchdog timer or
interval timer. If used as an interval timer, the WDT generates an interval timer interrupt request
when TCNT overflows. If used as a watchdog timer, the WDT generates a reset signal when
TCNT overflows.
Bit 6: WT/IT IT IT IT
Description
0 Interval timer: requests interval timer interrupts
1 Watchdog timer: generates a reset signal
Bit 5—Timer Enable (TME): Selects whether TCNT runs or is halted.
When WT/IT = 1, clear the SYSCR software standby bit (SSBY) to 0, then set the TME to 1.
When SSBY is set to 1, clear TME to 0.
Bit 5: TME Description
0 TCNT is initialized to H'00 and halted
1 TCNT is counting and CPU interrupt requests are enabled
Bits 4 and 3—Reserved: Read-only bits, always read as 1.
Bits 2 to 0—Clock Select 2 to 0 (CKS2/1/0): These bits select one of eight internal clock sources,
obtained by prescaling the system clock (φ), for input to TCNT.
Bit 2: CKS2 Bit 1: CKS1
0 0
1
1 0
1
Bit 0: CKS0 Description
φ/2
0
φ/32
1
φ/64
0
φ/128
1
φ/256
0
φ/512
1
φ/2048
0
φ/4096
1
Rev. 3.00 Mar 21, 2006 page 427 of 814
Section 12 Watchdog Timer
(Initial value)
(Initial value)
(Initial value)
REJ09B0302-0300