AD1846 Analog Devices, AD1846 Datasheet - Page 17

• Manufacturer Part Number: AD1846
• Description: Low Cost Parallel-port 16-bit Soundport Stereo Codec
• Manufacturer: Analog Devices

REV. A
The contents of the Clock and Data Format Register cannot be changed except when the AD1846 is in Mode Change Enable (MCE) state.
Write attempts to this register when the AD1846 is not in the MCE state will not be successful.
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CFS2:0
S/M
C/L
FMT
This register’s initial state after reset is “x000 0000.”
Clock and Data Format Register (IXA3:0 = 8)
res
IXA3:0
8
Clock Source Select. These bits select the crystal clock source which will be used for the audio sample rates.
0
1
Clock Frequency Divide Select. These bits select the audio sample rate frequency. The actual audio sample rate depends
on which crystal clock source is selected and the frequency of that source.
Note that the AD1846’s internal oscillators can be driven by external clock sources at the crystal input pins. If an external
clock source is applied, it will be divided down by the selected Divide Factor. It need not be at the recommended crystal
frequencies.
Stereo/Mono Select. This bit determines how the audio data streams are formatted. Selecting stereo will result with alter-
nating samples representing left and right audio channels. Mono playback plays the same audio sample on both channels.
Mono capture only captures data from the left audio channel.
0
1
Companded/Linear Select. This bit selects between a linear digital representation of the audio signal or a nonlinear, com-
panded format for all input and output data. The type of linear PCM or the type of companded format is defined by the
FMT bits.
0
1
Format Select. This bit defines the format for all digital audio input and outputs based on the state of the C/L bit.
Reserved for future expansion. Always write a zero to this bit.
XTAL1 (24.576 MHz)
XTAL2 (16.9344 MHz)
Mono
Stereo
Linear PCM
Companded
Data 7
res
CFS
0
1
2
3
4
5
6
7
0
1
Linear PCM (C/L = 0)
8-bit Unsigned PCM
16-bit Twos-Complement PCM
Data 6
FMT
Divide
Factor
3072
1536
896
768
448
384
512
2560
Data 5
C/L
XTAL1
24.576 MHz
8.0 kHz
16.0 kHz
27.42857 kHz
32.0 kHz
Not Supported
Not Supported
48.0 kHz
9.6 kHz
Data 4
–17–
S/M
Companded (C/L = 1)
8-bit -law Companded
8-bit A-law Companded
Data 3
CFS2
XTAL2
16.9344 MHz
5.5125 kHz
11.025 kHz
18.9 kHz
22.05 kHz
37.8 kHz
44.1 kHz
33.075 kHz
6.615 kHz
Data 2
CFS1
Data 1
CFS0
AD1846
Data 0
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