S-19400 Datasheet, PDF (19/36 Pages) Seiko Instruments Inc – Watchdog operation voltage range

FOR AUTOMOTIVE 125°C OPERATION LOW CURRENT CONSUMPTION WATCHDOG TIMER WITH RESET FUNCTION
Rev.2.1_00
S-19400/19401 Series
4. 4 Counter reset due to both rising and falling edges detection 2
(S-1940xCxxA, S-1940xFxxA, S-1940xIxxA, S-1940xLxxA)
VDD
CPOR
CWDT
WDI
WEN
(Active "H")
WDO
1234
1234 12 12
1234
30 31 32
12
Counter reset due to
both rising and falling edges detection Time-out after counter reset
RST
(S-19401 only)
Figure 32
5. WEN pin operation during charge-discharge operation to CWDT pin
When the WEN pin changes from "H" to "L" during the charge-discharge operation to the CWDT pin, the CWDT pin
performs the discharge operation. Moreover, the internal counter which counts the number of times of the
charge-discharge operation for the CWDT pin is also reset.
If the WEN pin changes to "H" again in this status, the CWDT pin initiates the charge-discharge operation.
VDD
CPOR
CWDT
WEN
(Active "H")
WDO
RST
(S-19401 only)
1234
1234
1234
12
31 32
12
Watchdog timer restarts the operation at WEN pin = "H"
Charge-discharge operation is stopped, counter reset
Figure 33
19