HT45F23/HT45F43
8-Bit Flash MCU with Op Amps & Comparators
Voice Output
Voice Control
The voice control register controls the DAC circuit. If the DAC circuit is not enabled, any DAH/DAL
outputs will be invalid. Writing a ²1² to the DACEN bit will enable the DAC circuit and channel the
DAC output to its corresponding I/O pin, while writing a ²0² to the DACEN bit will disable the DAC
circuit.
Audio Output and Volume Control - DAL, DAH, DACTRL
The audio output is 12-bits wide whose highest 8-bits are written into the DAH register and whose
lowest four bits are written into the highest four bits of the DAL register. Bits 0~3 of the DAL register
are always read as zero.
There are 8 levels of volume which are setup using the DACTRL register. The highest 3-bits of this
register are used for volume control and the DACEN bit is used to control the DAC function enable or
not. Once the DACEN bit is set to ²1², this will channel the DAC output to the I/O pin and disable the
original I/O pin shared function.
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7
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DACTRL Register
Bit
Name
R/W
7
VOL2
R/W
0
6
5
4
3
2
1
0
VOL1
R/W
0
VOL0
R/W
0
DACEN
R/W
0
¾
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POR
Bit 7~5
Bit 4~1
Bit 0
VOL2~VOL0: DAC volume control data
unimplemented, read as ²0²
DACEN: DAC enable control bit
0: disable
1: enable
Note: When the DACEN is set to ²1², the DAC signal will be channeled to the I/O pin and
disable the original I/O pin shared function.
Rev. 1.20
129
September 15, 2011
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
