Table 7-1. tWD Scaling with SET0 Pin Only (Pin Configuration A)

WATCHDOG TIME SCALING SELECTION

tWD

SET0 = 0

SET0 = 1

A

10ms

20ms

B

10ms

40ms

C

10ms

80ms

D

10ms

160ms

E

10ms

320ms

F

10ms

640ms

G

10ms

1280ms

For pinouts which offer both SET0 & SET1 pins to the user, the tWD multiplier value is decided based on the

Watchdog Time Scaling selector in the Section 4 section. Two SETx pins offer 3 different time scaling options.

The SET[1:0] = 0b'01 combination disables the watchdog operation. Table 7-2 showcases an example of the tWD

values for different SET[1:0] logic levels when using Watchdog Time setting as option G = 100ms. The package

pin out selected does not offer WD-EN pin.

Table 7-2. tWD Scaling with SET0 & SET1 Pins, WD-EN Pin Not Available (Pin Configuration B)

WATCHDOG TIME

SCALING SELECTION

tWD

SET[1:0] = 0b'00

SET[1:0] = 0b'01

SET[1:0] = 0b'10

SET[1:0] = 0b'11

A

100ms

Watchdog disable

200ms

400ms

B

100ms

Watchdog disable

400ms

800ms

C

100ms

Watchdog disable

800ms

1600ms

D

100ms

Watchdog disable

1600ms

3200ms

E

100ms

Watchdog disable

3200ms

6400ms

F

100ms

Watchdog disable

6400ms

12800ms

G

100ms

Watchdog disable

12800ms

25600ms

Selected pinout option can offer WD-EN pin along with SET[1:0] pins (Pin Configuration C, D). With this pinout,

the WD-EN pin controls watchdog enable and disable operation. The SET[1:0] = 0b'01 combination operates as

SET[1:0] = 0b'00.

Make sure the tWD value with SETx multiplier does not exceed 640s. If a selection of timer and multiplier results

in tWD > 640s, the timer value is restricted to 640s.

Figure 7-9 to Figure 7-11 diagrams show the timing behavior with respect to SETx status changes.

WDO

WDI

ttWDt

WD_EN = 1

ttWDt

ttWDt

ttWD X nt

SETx

ttWD X nt

ttWD X mt

ttWD X mt

WD multiplier = 1

WD multiplier = n

WD multiplier = m

Figure 7-9. Watchdog Behavior with SETx Pin Status

TPS35-Q1

SLVSGE8B – NOVEMBER 2022 – REVISED AUGUST 2024

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