WATCHDOG TIMER
[Precautions for watchdog timer]
[Precautions for watchdog timer]
1. When dummy data has been written to address 6016 with the 16-bit data length, writing to address 6116
is simultaneously performed. Accordingly, when the user does not want to change the contents of the
watchdog timer frequency select bit (bit 0 at address 6116) and watchdog timer clock source select bits
at STP termination (bits 6, 7 at address 6116), be sure to write again the values which are currently set
in these bits, simultaneously with writing to address 6016
.
2. When the STP instruction is executed, the watchdog timer stops its operation. If the STP instruction’s
code (3116, 3016) has accidentally been executed owing to a program runaway, the watchdog timer stops
its operation. Therefore, in the system where the watchdog timer is used to detect a program runaway,
we recommend that the STP instruction invalidity select bit (bit 0 at address 6216) = “1.” (STP instruction
is invalid.) Refer to section “15.3 Stop mode.”
7906 Group User’s Manual Rev.2.0
14-8
RENESAS [ RENESAS TECHNOLOGY CORP ]
