CS4216 Datasheet, PDF (22/58 Pages) Cirrus Logic – 16-Bit Stereo Audio Codec

CS4216
port is used asynchronously to the audio port,
the noise performance may be slightly degraded
due to this asynchronous digital noise.
Since control data does not need to be accessed
each audio frame, an interrupt pin, MF5:INT, is
included in this mode and will go low when
status has changed. The control port serial data
format is illustrated in Figure 14. The control
port uses one of the multifunction pins as a chip
select line, MF4:CCS, that must be low for en-
tering control data. Although only 23 bits
contain useful data on MF2:CDIN, a minimum
of 31 bits must be written. If more than 31 bits
are written without toggling MF4:CCS, only the
first 31 are recognized. MF1:CDOUT contains
SCLK to CLKIN Ratio Fs (kHz) Fs (kHz)
BPF BPF BPF with CLKIN with CLKIN
128 64 32 12.288 MHz 11.2896 MHz
2
4
8
3
6
12
4
8
16
48.00
32.00
24.00
44.10
29.40
22.05
5
10 20
19.20
17.64
6
12 24
8
16 32
16.00
12.00
14.70
11.025
10 20 40
9.60
8.82
12 24 48
8.00
7.35
Table 9. SM4-Slave, Fs Select.
status information that is output on the rising
edge of MF3:CCLK. Status information is re-
peated at the end of the frame, bits 25
through 30, to allow a simple 8-bit shift and
latch register to store the most important status
information using the rising edge of MF4:CCS at
the latch control (see Figure 17).
Applications of SM4
Figure 15 illustrates one method of using serial
mode 4 wherein a DSP controls the audio serial
port and a microcontroller controls the control
port. Each controller is run independently and
the micro updates the control information only
when needed, or when an interrupt from the
CS4216 occurs.
Figure 16 illustrates the minimum interface to
the CS4216. In this application, the DSP sends
and receives stereo DAC and ADC information.
The CS4216 is configured for 32 bits per frame,
Master sub-mode. The control data resets to all
zeros, which configures the CS4216 as a simple
stereo codec: no gain, no attenuation, line inputs
#1, and not muted.
Figure 17 illustrates how to use all the CS4216
features with a low cost DSP that cannot support
the interrupt rate of SM3. Using SM4 (32 bits
MF4:CCS
MF3:CCLK
MF2:CDIN
MF1:CDOUT
22
4 _Left
0 4 _Right
0
M
In
3 _Left 0 3 _Right 0
0
D/A Att.
D/A Att.
Sel. A/D Gain A/D Gain 0 0 0 0 0 0 0 0
103
0
10
0 Err Version 0 0 0 1 Err
Figure 14. SM4 - Control Serial Port
DS83F2