Holtek BS66F340 - Page 83

Rev. 1.60 82 August 20, 2019 Rev. 1.60 83 August 20, 2019
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
• RSTC Register
Bit 7 6 5 4 3 2 1 0
Name RSTC7 RSTC6 RSTC5 RSTC4 RSTC3 RSTC2 RSTC1 RSTC0
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 RSTC7~RSTC0: Reset function control
01010101: No operation
10101010: No operation
Other values: Reset MCU
If these bits are changed due to adverse environmental conditions, the microcontroller
will be reset. The reset operation will be activated after 2~3 LIRC clock cycles and the
RSTF bit in the RSTFC register will be set to 1.
• 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 ag
0: Not occurred
1: Occurred
This bit is set to 1 by the RSTC control register software reset and cleared by the
application program. Note that this bit can only be cleared to 0 by the application
program.
Bit 2 LVRF: LVR function reset ag
Described elsewhere.
Bit 1 LRF: LVR control register software reset ag
Described elsewhere.
Bit 0 WRF: WDT control register software reset ag
Described elsewhere.
Low Voltage Reset – LVR
The microcontroller contains a low voltage reset circuit in order to monitor the supply voltage of the
device. The LVR function is always enabled with a specic LVR voltage, V
LVR
. If the supply voltage
of the device drops to within a range of 0.9V~V
LVR
such as might occur when changing the battery,
the LVR will automatically reset the device internally and the LVRF bit in the RSTFC register will
also be set to 1. For a valid LVR signal, a low supply voltage, i.e., a voltage in the range between
0.9V~ V
LVR
must exist for a time greater than that specied by t
LVR
in the LVD/LVR characteristics.
If the low supply voltage state does not exceed this value, the LVR will ignore the low supply
voltage and will not perform a reset function. The actual V
LVR
value can be selected by the LVS
bits in the LVRC register. If the LVS7~LVS0 bits have any other value, which may perhaps occur
due to adverse environmental conditions such as noise, the LVR will reset the device after 2~3 f
LIRC
clock cycles. When this happens, the LRF bit in the RSTFC register will be set to 1. After power
on the register will have the value of 01010101B. Note that the LVR function will be automatically
disabled when the device enters the power down mode.