PIC32MX440F256H-80I Datasheet, PDF (564/646 Pages) Microchip Technology – 64/100-Pin General Purpose and USB 32-Bit Flash Microcontrollers

PIC32MX3XX/4XX
26.2.9 WDT POSTSCALERS
The WDT has a 5-bit postscaler to create a wide variety
of time-out periods. This postscaler provides 1:1
through 1: 1048576 divider ratios. Time-out periods
that range between 1 ms and 1048.576 seconds
(nominal) can be achieved using the postscaler.
The postscaler settings are selected using the WDTPS
bits in the DEVCFG1 Configuration register. The time-
out period of the WDT is calculated as follows:
EQUATION 26-1: WDT TIME-OUT PERIOD
CALCULATIONS
WDT Period = 1 ms • 2 ^Prescaler
TABLE 26-5: WDT TIME-OUT PERIOD VS.
POSTSCALER SETTINGS
FWDTPS<4:0>
Postscaler ^Time-out
Ratio
Period
00000
1:1
1 ms
00001
1:2
2 ms
00010
1:4
4 ms
00011
1:8
8 ms
00100
1:16
16 ms
00101
1:32
32 ms
00110
1:64
64 ms
00111
1:128
128 ms
01000
1:256
256 ms
01001
1:512
512 ms
01010
1:1024
1.024 s
01011
1:2048
2.048 s
01100
1:4096
4.096 s
01101
1:8192
8.192 s
01110
1:16384
16.384 s
01111
1:32768
32.768 s
10000
1:65536
65.536 s
10001
1:131072
131.072 s
10010
1:262144
262.144 s
10011
1:524288
524.288 s
10100
1:1045876
1048.576 s
Note 1: All other combinations will result in an
operation as if the prescaler was set to
10100.
2: The periods listed are based on a 32 kHz
(nominal) input clock.
DS61143E-page 562
Preliminary
© 2008 Microchip Technology Inc.