Rev. 1.10
52
November 26, 2019
Rev. 1.10
53
November 26, 2019
HT68FB240
USB Low Speed Flash MCU
Watchdog Time-out Reset during Normal Operation
The Watchdog time-out Reset during normal operation is the same as a hardware RES pin reset
except that the Watchdog time-out flag TO will be set to "1".
WDT Time-out Reset during Normal Operation Timing Chart
Watchdog Time-out Reset during SLEEP or IDLE Mode
The Watchdog time-out Reset during SLEEP or IDLE Mode is a little different from other kinds
of reset. Most of the conditions remain unchanged except that the Program Counter and the Stack
Pointer will be cleared to "0" and the TO flag will be set to "1". Refer to the A.C. Characteristics for
t
SST
details.
WDT Time-out Reset during Sleep Timing Chart
WDTC Register Software Reset
A WDTC software reset will be generated when a value other than "10101" or "01010", exist in the
highest five bits of the WDTC register. The WRF bit in the CTRL register will be set high when this
occurs, thus indicating the generation of a WDTC software reset.
• WDTC Register
Bit
7
6
5
4
3
2
1
0
Name
WE4
WE3
WE2
WE1
WE0
WS2
WS1
WS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
1
0
1
0
0
1
1
Bit 7~3
WE4~WE0:
WDT function software control
10101: disable
01010: enable (default)
Other: reset MCU
When these bits are changed to any other values due to environmental noise the
microcontroller will be reset; this reset operation will be activated after 2~3 LIRC
clock cycles and the WRF bit in the CTRL register will be set to 1 to indicate the reset
source.
Bit 2~0
WS2~WS0:
WDT time-out period selection
Described
elsewhere