SH7020 Datasheet, PDF (355/509 Pages) Renesas Technology Corp – SuperH™ RISC engine

12.4.4 System Reset With WDTOVF
If a WDTOVF signal is input to the RES pin, the LSI cannot initialize correctly. Avoid logical
input of the WDTOVF output signal to the RES input pin. To reset the entire system with the
WDTOVF signal, use the circuit shown in figure 12.9.
Reset input
SuperH
microprocessor
RES
Reset signal to
entire system
WDTOVF
Figure 12.9 Example of a System Reset Circuit with a WDTOVF Signal
12.4.5 Internal Reset With the Watchdog Timer
If the RSTE bit is cleared to 0 in the watchdog timer mode, the LSI will not reset internally when a
TCNT overflow occurs, but the TCNT and TCSR in WDT will reset.
RENESAS 339