Texas Instruments PCM5142 Evaluation Module PCM5142EVM-U PCM5142EVM-U Fiche De Données
Codes de produits
PCM5142EVM-U
PCM51xx
Audio DAC
Linear
Regulator
3V3
10 F
GND
GND
SMPS
6V
GND
XSMT
110V / 220V
MCU GPIO
“mute” signal
3.3V
XSMT
I2S Clocks
SCK, BCK, LRCK
3msec
VDD
0V
High
Low
High
Low
Time
SLAS759A – AUGUST 2012 – REVISED SEPTEMBER 2012
2. Stop I
2
S clocks (SCK, BCK, LRCK) 3ms before powerdown as shown below:
Unplanned Shutdown
Many systems use a low-noise regulator to provide an AVDD 3.3V supply for the DAC. The XSMT Pin can take
advantage of such a feature to measure the pre-regulated output from the system SMPS to mute the DAC before
the entire SMPS discharges.
advantage of such a feature to measure the pre-regulated output from the system SMPS to mute the DAC before
the entire SMPS discharges.
shows how to configure such a system to use the XSMT pin. The XSMT
pin can also be used in parallel with a GPIO pin from the system microcontroller/DSP or Power Supply.
Figure 80. Using the XSMT Pin
Software Control
SPI Interface
The SPI interface is a 4-wire synchronous serial port which operates asynchronously to the serial audio interface
and the system clock (SCK). The serial control interface is used to program and read the on-chip mode registers.
and the system clock (SCK). The serial control interface is used to program and read the on-chip mode registers.
The control interface includes MISO (pin 24), MOSI (pin 11), MC (pin 12), and MS (pin 18). MISO (Master In
Slave Out) is the serial data output, used to read back the values of the mode registers; MOSI (Master Out Slave
In) is the serial data input, used to program the mode registers.
Slave Out) is the serial data output, used to read back the values of the mode registers; MOSI (Master Out Slave
In) is the serial data input, used to program the mode registers.
MC is the serial bit clock, used to shift data in and out of the control port by falling edge of MC, and MS is the
mode control enable with LOW active, used to enable the internal mode register access. If feedback from the
device is not required, the MISO pin can be assigned to GPIO1 by register control.
mode control enable with LOW active, used to enable the internal mode register access. If feedback from the
device is not required, the MISO pin can be assigned to GPIO1 by register control.
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Copyright © 2012, Texas Instruments Incorporated
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