HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 616

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 13 Watchdog Timer
Bit 6
WT/IT
0
1
Notes: 1. The WDTOVF pin function cannot be used in the F-ZTAT versions.
Bit 5—Timer Enable (TME): Selects whether TCNT runs or is halted.
Bit 5
TME
0
1
Bits 4 and 3—Reserved: These bits cannot be modified and are always read as 1.
Bits 2 to 0—Clock Select 2 to 0 (CKS2 to CKS0): These bits select one of eight internal clock
sources, obtained by dividing the system clock (φ), for input to TCNT.
Bit 2
CKS2
0
1
Note: * The overflow period is the time from when TCNT starts counting up from H'00 until overflow
Rev.6.00 Sep. 27, 2007 Page 586 of 1268
REJ09B0220-0600
occurs.
2. For details of the case where TCNT overflows in watchdog timer mode, see section
Bit 1
CKS1
0
1
0
1
13.2.3, Reset Control/Status Register (RSTCSR).
Description
Interval timer: Sends the CPU an interval timer interrupt request (WOVI)
when TCNT overflows
Watchdog timer: Generates the WDTOVF signal *
Description
TCNT is initialized to H'00 and halted
TCNT counts
Bit 0
CKS0
0
1
0
1
0
1
0
1
Description
Clock
φ/2 (Initial value)
φ/64
φ/128
φ/512
φ/2048
φ/8192
φ/32768
φ/131072
Overflow Period (when φ = 20 MHz) *
25.6 µs
819.2 µs
1.6 ms
6.6 ms
26.2 ms
104.9 ms
419.4 ms
1.68 s
1
when TCNT overflows *
(Initial value)
(Initial value)
2