h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 448

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 12 Watchdog Timer
Table 12.1 WDT Registers
Notes: 1. Lower 16 bits of the address.
12.2
12.2.1
TCNT is an 8-bit readable/writable * up-counter.
When the TME bit is set to 1 in TCSR, TCNT starts counting pulses generated from the internal
clock source selected by bits CKS2 to CKS0 in TCSR. When the count overflows (changes from
H'FF to H'00), an internal reset, a NMI interrupt (only WDT1), or an interval timer interrupt
(WOVI) is generated, depending on the mode selected by the WT/IT bit in TCSR.
TCNT is initialized to H'00 by a reset, in hardware standby mode, or when the TME bit is cleared
to 0. It is not initialized in software standby mode.
Note: * TCNT is write-protected by a password to prevent accidental overwriting. For details see
Rev. 5.00 Sep 22, 2005 page 422 of 1136
REJ09B0257-0500
Channel Name
0
1
Bit
Initial value :
R/W
2. For details of write operations, see section 12.2.4, Notes on Register Access.
3. Only a write of 0 is permitted to bit 7, to clear the flag.
section 12.2.4, Notes on Register Access.
Register Descriptions
Timer Counter (TCNT)
Timer control/status register 0 TCSR0
Timer counter 0
Reset control/status register
Timer control/status register 1 TCSR1
Timer counter 1
:
:
R/W
7
0
R/W
6
0
R/W
Abbreviation R/W
TCNT0
RSTCSR0
TCNT1
5
0
R/W
4
0
R/(W) *
R/W
R/(W) *
R/(W) *
R/W
R/W
3
0
3
3
3
Initial Value Write *
H'18
H'00
H'1F
H'00
H'00
R/W
2
0
H'FF74 H'FF74
H'FF74 H'FF75
H'FF76 H'FF77
H'FFA2 H'FFA2
H'FFA2 H'FFA3
R/W
1
0
Address *
2
Read
R/W
0
0
1