Rev. 1.00
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Rev. 1.00
43
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HT66FM5440
Brushless DC Motor A/D Flash MCU
HT66FM5440
Brushless DC Motor A/D Flash MCU
LVR
Internal Reset
t
RSTD
+ t
SST
Low Voltage Reset Timing Chart
• LVRC Register
Bit
7
6
5
4
3
2
1
0
Name
LVS�
LVS6
LVS5
LVS4
LVS3
LVS�
LVS1
LVS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
1
0
1
0
1
0
1
Bit 7~0
LVS7~LVS0
: LVR Voltage Select control
01010101: 3.8V
00110011: 3.8V
10011001: 3.
8
V
10101010: 3.8V
Any other value: Generates MCU reset – register is reset to POR value
When an actual low voltage condition occurs, as specified by the defined LVR voltage
value above, an MCU reset will be generated. The reset operation will be activated
after 2~3 f
LIRC
clock cycles. In this situation the register contents will remain the same
after such a reset occurs.
Any register value, other than the four values above, will also result in the generation
of an MCU reset. The reset operation will be activated after 2~3 f
LIRC
clock cycles.
However in this situation the register contents will be reset to the POR value.
• CTRL Register
Bit
7
6
5
4
3
2
1
0
Name
FSYSON
—
—
—
—
LVRF
LRF
WRF
R/W
R/W
—
—
—
—
R/W
R/W
R/W
POR
0
—
—
—
—
x
0
0
"x": �nknown
Bit 7
FSYSON
: f
SYS
Control in IDLE Mode
Described elsewhere
Bit 6~3
Unimplemented, read as "0"
Bit 2
LVRF
: LVR function reset flag
0: Not occur
1: Occurred
This bit is set to 1 when a specific Low Voltage Reset situation condition occurs. This
bit can only be cleared to 0 by the application program.
Bit 1
LRF
: LVR control register software reset flag
0: Not occur
1: Occurred
This bit is set to 1 if the LVRC register contains any non-defined LVR voltage register
values. This in effect acts like a software-reset function. This bit can only be cleared to
0 by the application program.
Bit 0
WRF
: WDT control register software reset flag
Describe elsewhere.