Rev. 1.00
60
September 11, 2018
Rev. 1.00
61
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC 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
LVS7
LVS6
LVS5
LVS4
LVS3
LVS2
LVS1
LVS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
1
1
0
0
1
1
0
Bit 7~0
LVS7~LVS0
: LVR voltage select
01100110: 1.65V
01010101: 1.90V
00110011: 2.55V
10011001: 3.15V
10101010: 3.80V
11110000: LVR disable
Any other value: Generates
a
MCU reset – register is reset to POR value
When an actual low voltage condition occurs, as specified by one of the five defined
LVR voltage values above, an MCU reset will be generated. The reset operation
will be activated after the low voltage condition keeps more than a t
LVR
time. In this
situation the register contents will remain the same after such a reset occurs.
Any register value, other than the five defined LVR values above, will also result in the
generation of an MCU reset. The reset operation will be activated after a delay time,
t
SRESET
. However in this situation the register contents will be reset to the POR value.
• 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 the RES Pin Reset section.
Bit 2
LVRF
: LVR function reset flag
0: Not occurred
1: Occurred
This bit is set to 1 when a specific low voltage reset condition occurs. Note that this bit
can only be cleared to 0 by the application program.
Bit 1
LRF
: LVR control register software reset flag
0: Not occurred
1: Occurred
This bit is set to 1 by the LVRC control register contains any undefined LVR voltage
register values. This in effect acts like a software-reset function. Note that this bit can
only be cleared to 0 by the application program.
Bit 0
WRF
: WDT control register software reset flag
Refer to the Watchdog Timer Control Register section.