HD6473847RHV Datasheet, PDF (289/546 Pages) Renesas Technology Corp – Renesas 8-Bit Single-Chip Microcomputer H8 Family / H8/300L Super Low Power Series

Figure 9.13 shows an example of watchdog timer operation.
Example: With 30-ms overflow period when φ = 4 MHz
4 × 10⁶ _{× 30 × 10–3 = 14.6}
8192
Therefore, 256 – 15 = 241 (H'F1) is set in TCW.
H'FF
H'F1
TCW
count value
Section 9 Timers
TCW overflow
H'00
Start
H'F1 written
to TCW
Internal reset
signal
H'F1 written to TCW
Reset generated
512 φ_osc clock cycles
Figure 9.13 Example of Watchdog Timer Operation
Rev. 7.00 Mar. 08, 2010 Page 257 of 510
REJ09B0024-0700