CS4216 Datasheet, PDF (40/58 Pages) Cirrus Logic – 16-Bit Stereo Audio Codec

CDB4216
GENERAL DESCRIPTION
The CDB4216/8 was designed to provide an
easy platform for evaluating the performance of
the CS4216 and CS4218 Stereo Audio Codecs.
Since the evaluation board contains a proper lay-
out and is performance tested, the user can
concentrate on engineering the rest of the system
thereby reducing the development time. The lay-
out should also be used as a guideline for
obtaining the best possible performance from the
CS4216 or CS4218. Lastly, the board can be
used as a benchmark and debugging tool for user
developed PCBs.
The evaluation board supports all serial modes
and includes decode circuitry to ease the selec-
tion of the serial mode and sub-mode of interest.
All serial interfaces are buffered for easy connec-
tion to the serial port of a DSP or other serial
device. The board can also be placed in a loop
back mode where the digital data is looped back
allowing an analog in to analog out testing vehi-
cle without an external processor. A single +5V
supply is all that is needed to power the board.
Analog inputs consist of a pair of line input buff-
ers (LIN1, RIN1) designed to accept a maximum
audio signal of 2V_RMS and BNC-to-phono
adapters are included to support various test con-
figurations. The second pair of inputs contain a
example microphone input buffer supported by
two ¹/₄" mono jacks that are designed to accept
standard single-ended dynamic or condenser mi-
crophones.
The line outputs are supplied via BNC connec-
tors with two more BNC-to-phono adapters.
The film plots of the evaluation board are in-
cluded to provide an example of the optimum
layout, grounding, and decoupling arrangement
for the CS4216 or CS4218.
SELECTING A SERIAL MODE
The CS4216 supports four serial modes and
many sub-modes, and the CS4218 supports three
serial modes and sub-modes. Selecting the most
appropriate mode for a given application can be
time consuming. The CDB4216/8 contains a DIP
switch that simplifies this selection. Since the
CS4216/8 contains many multifunction pins, the
DIP switch lets the user select the configuration
and two PLDs decode the proper multifunction
pin values. Since these PLDs are only used to
simplify the configuration of the device, they
would not be needed in an end application which
would hard wire the configuration pins. Table 4
describes the multifunction pin values for a
given DIP switch setting. The PAL equations for
DIP switch decoding are given in Figures 8 and
9.
All references to SM1 and SM2 apply only to
the CS4216. All references to SM3-MM, SM3-
MS, and I²S apply only to the CS4218.
Serial Port Format
Table 1 lists the DIP switches used to select the
serial mode. SPF2 and SPF1 select one the four
serial modes of the CS4216 or one of three serial
modes for the CS4218. MA selects master
(MA = 1) or slave and is only useful in serial
modes 3 and 4. The majority of users select
SPF2 SPF1 MA
0
0
x
0
1
x
1
0
0
1
0
1
1
1
0
1
1
1
Serial Mode
SM1
SM2
SM3
SM3
SM4
SM4
Slave
Slave
Slave
Master
Slave
Master
Table 1. DIP Switch, Serial Modes
40
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