HD6417706 RENESAS [Renesas Technology Corp], HD6417706 Datasheet - Page 350

• Manufacturer Part Number: HD6417706
• Description: Renesas 32-Bit RISC Microcomputer Super RISC engine Family/SH7700 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

11.2
The WDT has two registers that select the clock, switch the timer mode, and perform other
functions. Refer to section 23, List of Registers, for more details of the addresses and access sizes.
11.2.1
The watchdog timer counter (WTCNT) is an 8-bit read/write register that increments on the
selected clock. When an overflow occurs, it generates a reset in watchdog timer mode and an
interrupt in interval time mode. The WTCNT is initialized to H'00 only by a power-on reset
through the RESETP pin. Use a word access to write to the WTCNT, with H'5A in the upper byte.
Use a byte access to read WTCNT.
Note: The watchdog timer counter (WTCNT) is more difficult to write to than other registers to
11.2.2
The watchdog timer control/status register (WTCSR) is an 8-bit read/write register composed of
bits to select the clock used for the count, bits to select the timer mode, and overflow flags. The
WTCSR is initialized to H'00 only by a power-on reset through the RESETP pin. When a WDT
overflow causes an internal reset, the WTCSR retains its value. When used to count the clock
settling time for canceling a software standby, it retains its value after counter overflow. Use a
word access to write to the WTCSR, with H'A5 in the upper byte. Use a byte access to read
WTCSR.
Rev. 4.00, 03/04, page 304 of 660
Bit
7 to 0
Watchdog timer counter (WTCNT)
Watchdog timer control/status register (WTCSR)
prevent from the erroneous writing to the register. Refer to section 11.2.3 Notes on Register
Access.
Register Description
Watchdog Timer Counter (WTCNT)
Watchdog Timer Control/Status Register (WTCSR)
Bit Name
Initial Value R/W
All 0
R/W
Description
8-bit counter