Datasheet
71M6521DE/DH/FE Data Sheet 
Rev 3    Page: 29 of 107 
Special Function Registers for the WD Timer 
Interrupt Enable 0 Register (IEN0): 
MSB  LSB 
EAL  WDT  ET2  ES0  ET1  EX1  ET0  EX0 
Table 27: The IEN0 Register (see also Table 32) 
Bit 
Symbol 
Function 
IEN0.6  WDT 
Watchdog timer refresh flag. 
Set to initiate a refresh of the watchdog timer. Must be set directly before SWDT is 
set to prevent an unintentional refresh of the watchdog timer. WDT is reset by 
hardware 12 clock cycles after it has been set. 
Table 28: The IEN0 Bit Functions (see also Table 32) 
Note: The remaining bits in the IEN0 register are not used for watchdog control 
Interrupt Enable 1 Register (IEN1): 
MSB  LSB 
EXEN2  SWDT  EX6  EX5  EX4  EX3  EX2   
Table 29: The IEN1 Register (see also Tables 30/31) 
Bit 
Symbol 
Function 
IEN1.6  SWDT 
Watchdog timer start/refresh flag. 
Set to activate/refresh the watchdog timer. When directly set after setting WDT, a 
watchdog timer refresh is performed. Bit SWDT is reset by the hardware 12 clock 
cycles after it has been set. 
Table 30: The IEN1 Bit Functions (see also Tables 30/31) 
Note: The remaining bits in the IEN1 register are not used for watchdog control 
Interrupt Priority 0 Register (IP0): 
MSB  LSB 
--  WDTS  IP0.5  IP0.4  IP0.3  IP0.2  IP0.1  IP0.0 
Table 31: The IP0 Register (see also Table 45) 










