CS4225 Datasheet, PDF (27/30 Pages) Cirrus Logic – Digital Audio Conversion System

CS4225
SDA/CDOUT/CKF0 - Serial Control Data Out / Clock Select
In I²C^® mode, SDA is the control data I/O line. In SPI software control mode, CDOUT is the
output data from the control port interface on the CS4225.
In hardware control mode, CKF0 and CKF1 controls the clock frequency of CLKOUT.
DATAUX - Auxiliary Data Input
DATAUX is the auxiliary audio data input line, usually connected to an external digital audio
source.
LRCKAUX - Auxiliary Word Clock Input or Output
In auxiliary slave mode, LRCKAUX is a word clock (at Fs) from an external digital audio
source. LRCKAUX can be used as the clock reference for the internal PLL. In auxiliary master
mode, LRCKAUX is a word clock output (at Fs) to clock an external digital audio source.
SCLKAUX - Auxiliary Bit Clock Input or Output
In auxiliary slave mode, SCLKAUX is the serial data bit clock from an external digital audio
source, used to clock in data on DATAAUX. SCLKAUX can be used as the clock reference for
the internal PLL. In auxiliary master mode, SCLKAUX is a serial data bit clock output.
AD0/IS0, AD1/IS1 - Input Select Control Pins
In software mode, these pins are part of the chip address.
In hardware mode, IS0 and IS1 select the audio input source from between 4 pairs of signals
(AIN1, AIN2 and AIN3) and DATAUX.
H/S - Hardware or Software Control
Setting H/S high puts the CS4225 into hardware control mode, where many functions are
controlled by dedicated pins. When H/S is low, many chip functions are controlled via the
control port in SPI mode. When H/S is open circuit, then software mode I²C^® protocol is
selected for the control port. When floating H/S, a 100pF capacitor should be connected from
the H/S pin to ground, to reduce the possibility of external interference influencing the pin.
OVL - Overload Indicator
If either of the 2 16-bit audio ADCs, or the 12-bit ADC, is clipped, then this pin goes high.
Clock and Crystal Pins
XTI, XTO - Crystal connections
Input and output connections for the crystal which may be used to operate the CS4225.
Alternatively, a clock may be input into XTI.
CLKOUT - Master Clock Output
CLKOUT allows external circuits to be synchronized to the CS4225. Alternate output
frequencies are selectable by the control port or via hardware pins.
DS86PP8
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