Rev. 1.50
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Rev. 1.50
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HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
•
SADC2 Register
Bit
7
6
5
4
3
2
1
0
Name
�DPG�EN VBGEN VREFIPS VREFPS S�VRS3 S�VRS� S�VRS1 S�VRS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7
ADPGAEN
: A/D converter PGA function enable control
0: Disable
1: Enable
This bit controls the internal PGA function to provide various reference voltage for
the A/D converter. When the bit is set high, the internal reference voltage, V
R
, can be
used as the internal converted signal or reference voltage by the A/D converter. If the
internal reference voltage is not used by the A/D converter, then the PGA function
should be properly configured to conserve power.
Bit 6
VBGEN
: Internal Bandgap reference voltage enable control
0: Disable
1: Enable
This bit controls the internal Bandgap circuit on/off function to the A/D converter.
When the bit is set high, the Bandgap reference voltage can be used by the A/D
converter. If the Bandgap reference voltage is not used by the A/D converter and
the LVD or LVR function is disabled, then the bandgap reference circuit will be
automatically switched off to conserve power. When the Bandgap reference voltage
is switched on for use by the A/D converter, a time, t
BGS
, should be allowed for the
Bandgap circuit to stabilise before implementing an A/D conversion.
Bit 5
VREFIPS
: VREFI pin selection bit
0: Disable – VREFI pin is not selected
1: Enable – VREFI pin is selected
Bit 4
VREFPS
: VREF pin selection bit
0: Disable – VREF pin is not selected
1: Enable – VREF pin is selected
Bit 3~0
SAVRS3~SAVRS0
: A/D Converter reference voltage select
0000: V
DD
0001: V
REFI
0010: V
REFI
× 2
0011: V
REFI
× 3
0100: V
REFI
× 4
1001: Reserved, can not be used.
1010: V
BG
× 2
1011: V
BG
× 3
1100: V
BG
× 4
Others: V
DD
When the A/D converter reference voltage source is selected to derive from the
internal V
BG
voltage, the reference voltage which comes from the external VDD or
VREFI pin will be automatically switched off.