Rev. 1.10
74
October 23, 2020
Rev. 1.10
75
October 23, 2020
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
Bit 2~0
WS2~WS0
: WDT time-out period selection
000: 2
8
/f
LIRC
001: 2
10
/f
LIRC
010: 2
12
/f
LIRC
011: 2
14
/f
LIRC
100: 2
15
/f
LIRC
101: 2
16
/f
LIRC
110: 2
17
/f
LIRC
111: 2
18
/f
LIRC
These three bits determine the division ratio of the Watchdog Timer source clock,
which in turn determines the timeout period.
• RSTFC Register
Bit
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
“x”: unknown
Bit 7~4
Unimplemented, read as “0”
Bit 3
RSTF
: Reset
control register software reset flag
Refer to Internal Reset Control section.
Bit 2
LVRF
: LVR function reset flag
Refer to the Low Voltage Reset section.
Bit 1
LRF
: LVR control register software reset flag
Refer to the Low Voltage Reset section.
Bit 0
WRF
: WDT control register software reset flag
0: Not occurred
1: Occurred
This bit is set high by the WDT Control register software reset and cleared to zero
by the application program. Note that this bit can only be cleared to zero 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.
T
here are five
bits, WE4~WE0, in the WDTC register to offer additional enable/disable 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 a delay time, t
SRESET
. After power on these bits will have the value of 01010B.
WE4~WE0 Bits
WDT Function
10101B
Disable
01010B
Enable
Any other value
Reset MCU
Watchdog Timer Function Control
Under normal program operation, a Watchdog Timer time-out will initialise a device reset and set
the status bit TO. However, if the system is in the SLEEP or IDLE Mode, when a Watchdog Timer