AD1845JSTZ Datasheet, PDF (19/40 Pages) Analog Devices – Parallel-Port 16-Bit SoundPort Stereo Codec

AD1845
Clock and Data Format Register (IXA3:0 = 8)
IXA3:0
8
Data 7
FMT1
Data 6
FMT0
Data 5
C/L
Data 4
S/M
Data 3
CFS2
Data 2
CFS1
Data 1
CFS0
Data 0
CSS
NOTE: Placing the AD1845 in the Mode Change Enable (MCE) state is not required when changing the sample rate. However,
changes to FMT[1:0], C/L, and S/M require MCE or setting PEN = 0.
CSS
Clock Source Select. This bit in conjunction with CFS2:0 selects the audio sample rate frequency. See Figure 8
below. Note: MODE2 allows a wider range of sample rate frequencies to be selected by using the Frequency
Select Register (refer to Registers 22 and 23).
CFS2:0
S/M
C/L
FMT[1:0]
res
Clock Frequency Divide Select. These bits in conjunction with CSS select the audio sample frequency.
CFS2
0
0
0
0
E ₀
0
0
T ₀
1
1
E 1
1
1
L ¹
1
1
CFS1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
CFS0
CSS
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
Sample Rate
8.0
kHz
5.5125 kHz
16.0
kHz
11.025 kHz
27.42857 kHz
18.9
kHz
32.0
kHz
22.05 kHz
Reserved
37.8
kHz
Reserved
44.1
kHz
48.0
kHz
33.075 kHz
9.6
kHz
6.615 kHz
Figure 8. MODE1 Audio Sample Frequency Select
O _{Stereo/Mono Select. This bit determines how the audio data streams are formatted. Selecting stereo will result}
with alternating 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.
S ₀
Mono
1
Stereo
Companded/Linear Select. This bit selects between a linear digital representation of the audio signal or a nonlinear,
companded format for all input and output data. The type of linear PCM or the type of companded format is
B _{defined by the FMT bits.}
0
Linear PCM
1
Companded
O^{Format Select. The bits define the format for all digital audio input and outputs based on the state of the C/L bit.}
See Figure 9 for FMT and C/L bit settings that determine the audio data type format.
Reserved for future expansion. Always write a zero to this bit.
This register’s initial state after reset is “0000 0000.”
FMT1
FMT0
C/L
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
Audio Data Type
Linear, 8-Bit Unsigned PCM
µ-Law, 8-Bit Companded
Linear, 16-Bit Twos-Complement PCM Little Endian
A-Law, 8-Bit Companded
Reserved
Reserved
Linear, 16-Bit Twos Complement Big Endian
Reserved
Figure 9. Digital Audio Data Type
REV. C
–19–