AD1939 Analog Devices, AD1939 Datasheet - Page 12

• Manufacturer Part Number: AD1939
• Description: (AD1935 - AD1939) 4 ADC/8 DAC
• Manufacturer: Analog Devices

Serial Data Ports—Data Format
The eight DAC channels output or accept a common serial bit clock
and left-right framing clock to clock in the serial data. The four
ADC channels output or accept a common serial bit clock and left-
right framing clock to clock out the data. The clock signals are all
synchronous with the sample rate. In the AUX Modes, set in ADC
Control 1 and DAC Control 0, the DACs use the ADC serial bit
clock and left-right clock as the DAC clock pins are used for the
auxiliary ADC/DAC serial clocks.
The ADC and DAC serial data modes default to I
also be programmed for left-justified, right-justified and TDM
modes. The word width is 24 bits by default and can be
programmed for 16 or 20 bits. The normal TDM mode can be
daisy-chained with a second AD193X and will support 16 channels
AD1935/AD1936/AD1937/AD1938/AD1939
LRCLK
SDATA
LRCLK
SDATA
LRCLK
SDATA
LRCLK
SDATA
BCLK
BCLK
BCLK
BCLK
NOTES
1. DSP MODE DOES NOT IDENTIFY CHANNEL
2. LRCLK NORMALLY OPERATES AT f
3. BCLK FREQUENCY IS NORMALLY 64 × LRCLK BUT MAY BE OPERATED IN BURST MODE
MSB
MSB
MSB
MSB
LEFT CHANNEL
LEFT CHANNEL
LEFT CHANNEL
S
2
RIGHT JUSTIFIED MODE––SELECT NUMBER OF BITS PER CHANNEL
EXCEPT FOR DSP MODE WHICH IS 2 × f
S. The ports can
LEFT JUSTIFIED MODE––16 BITS TO 24 BITS PER CHANNEL
LSB
DSP MODE––16 BITS TO 24 BITS PER CHANNEL
I
2
S MODE––16 BITS TO 24 BITS PER CHANNEL
Figure 13. Stereo Serial Modes
LSB
LSB
Rev. PrI | Page 12 of 30
LSB
1/f
S
MSB
S
at 48 kHz, 8 channels at 96 kHz or 4 channels at 192 kHz. There is
also a dual-line TDM mode to support 8 channels at 192 kHz.
The special auxiliary modes are provided to allow two external
stereo ADCs and/or two external stereo DACs to be interfaced with
the AD193X to provide up to 8 in/12 out operation or 2 AD193Xs
to be chained for up to 16 in/16 out operation. These modes
provide a glueless interface to a single SHARC serial port, allowing
the DSP to access up to 16 channels of analog I/O. In these modes
many pins are redefined, see table 10. See Figure 18 for details of
these modes.
The following figures show the serial mode formats.
MSB
MSB
MSB
RIGHT CHANNEL
RIGHT CHANNEL
RIGHT CHANNEL
Preliminary Technical Data
LSB
LSB
LSB
LSB