16.3.2 Selecting WDT Clock Source
The Sleep Mode Counter always uses the 32 kHz LPRC clock source. The Run Mode Counter will use the clock source selected by the WDTRMCS bit in fuses Configuration Bits register DEVCFG2 to be either the 32 kHz LPRC clock or the PB1_CLK bus clock (sysclk). See WDTRMCS[1:0] bits in the CFGCON2(L) register from Related Links.