HT66FV130 Datasheet, PDF (83/259 Pages) Holtek Semiconductor Inc – Enhanced Voice Flash MCU

HT66FV130/HT66FV140
HT66FV150/HT66FV160
Enhanced Voice Flash MCU
RSTFC Register
Register
Bit
Name
7
6
5
4
3
2
1
0
Name
—
—
—
—
RSTF LVRF
LRF
WRF
R/W
—
—
—
—
R/W
R/W
R/W
R/W
POR
—
—
—
—
0
x
0
0
Bit 7~4 Unimplemented, read as "0"
"x": unknown
Bit 3
RSTF: Reset control register software reset flag
Described elsewhere.
Bit 2
LVRF: LVR function reset flag
Described elsewhere.
Bit 1
LRF: LVR control register software reset flag
Described elsewhere.
Bit 0
WRF: WDT control register software reset flag
0: Not occurred
1: Occurred
This bit is set to 1 by the WDT control register software reset and cleared by the
application program. Note that this bit can only be cleared to 0 by the application
program.
Watchdog Timer Operation
The Watchdog Timer operates by providing a device reset when its timer overflows. This means
that in the application program and during normal operation the user has to strategically clear the
Watchdog Timer before it overflows to prevent the Watchdog Timer from executing a reset. This is
done using the clear watchdog instruction. If the program malfunctions for whatever reason, jumps
to an unknown location, or enters an endless loop, the clear instruction will not be executed in the
correct manner, in which case the Watchdog Timer will overflow and reset the device. With regard to
the Watchdog Timer enable/disable function, there are five bits, WE4~WE0, in the WDTC register
to offer the enable/disable control and reset control of the Watchdog Timer. The WDT function will
be disabled when the WE4~WE0 bits are set to a value of 10101B while the WDT function will
be enabled if the WE4~WE0 bits are equal to 01010B. If the WE4~WE0 bits are set to any other
values, other than 01010B and 10101B, it will reset the device after 2~3 fLIRC clock cycles. After
power on these bits will have a value of 01010B.
WE4 ~ WE0 Bits
10101B
01010B
Any other value
WDT Function
Disable
Enable
Reset MCU
Watchdog Timer Enable/Disable Control
Rev. 1.50
83
December 06, 2016