BS66FV340 Datasheet, PDF (154/265 Pages) Holtek Semiconductor Inc – Enhanced Touch Voice A/D Flash MCU

BS66FV340/BS66FV350/BS66FV360
Enhanced Touch Voice A/D Flash MCU
Bit 5
Bit 4
Bit 3~0
ADCEN: A/D Converter function enable control
0: Disable
1: Enable
This bit controls the A/D internal function. This bit should be set to one to enable
the A/D converter. If the bit is set low, then the A/D converter will be switched off
reducing the device power consumption. When the A/D converter function is disabled,
the contents of the A/D data register pair known as SADOH and SADOL will be
unchanged.
ADRFS: A/D conversion data format select
0: A/D converter data format → SADOH = D [11:4]; SADOL = D [3:0]
1: A/D converter data format → SADOH = D [11:8]; SADOL = D [7:0]
This bit controls the format of the 12-bit converted A/D value in the two A/D data
registers. Details are provided in the A/D converter data register section.
SACS3~SACS0: A/D converter external analog input channel select
0000: External AN0 input
0001: External AN1 input
0010: External AN2 input
0011: External AN3 input
0100: External AN4 input
0101: External AN5 input
0110: External AN6 input
0111: External AN7 input
1xxx: Undefined, input floating.
These bits are used to select which external analog input channel is to be converted.
When the external analog input channel is selected, the SAINS bit field must set to
"000", "101" or "110". Details are summarized in the "A/D Converter Input Signal
Selection" table.
SADC1 Register
Bit
Name
R/W
POR
7
SAINS2
R/W
0
6
SAINS1
R/W
0
5
SAINS0
R/W
0
4
SAVRS1
R/W
0
3
SAVRS0
R/W
0
2
SACKS2
R/W
0
1
SACKS1
R/W
0
0
SACKS0
R/W
0
Bit 7~5
SAINS2~SAINS0: A/D converter input signal select
000: External source – External analog channel intput
001: Internal source – Internal Bandgap reference voltage, VBG.
010: Internal source – Internal Temperature sensor output voltage, VTSO.
011, 100: Internal source – Ground.
101, 110: External source – External analog channel input
111: Forbidden to be used
Care must be taken if the SAINS2~SAINS0 bits are set to "001", "010", "011" or
"100" to select the internal analog signal to be converted. When the internal analog
signal is selected to be converted, the SACS3~SACS0 bits must be set to "1xxx" to
make sure that the external analog channel input is floating. Otherwise, the external
channel input will be connected together with the internal analog signal. This will
result in unpredictable situations and irreversible damage.
Rev. 1.10
154
December 15, 2016