AN1836-AN21161 Analog Devices, AN1836-AN21161 Datasheet - Page 10

• Manufacturer Part Number: AN1836-AN21161
• Description: Interfacing the ADSP-21161 SIMD SHARC DSP to the AD1836 (24-bit/96 kHz) Multichannel Codec
• Manufacturer: Analog Devices

1. AD1836 -to- ADSP-21161 Serial Interface Overview
The AD1836 supports multiple I2S connections to DSP I2S ports. In an additional mode of operation, the AD1836 TDM serial
port functionality is very similar other Analog Devices SoundPort Codecs like the AD1819, AD1881 and AD1847. It’s
interface can communicates with a DSP or ASIC in a time-division multiplexed (TDM) mode, where DAC/ADC data are
received and transmitted in different timeslots in a TDM frame. The AD1836 codec register command/status information can
be accessed via an SPI-compatible slave port. The ADSP-21161 can access the slave SPI-compatible port either through the
SPORT interface or the SPI interface. The AD1836 includes 6, independent volume controls adjustable via the SPI slave port.
In this application note, we will only be discussing the simplified TDM interface.
interconnections will be discussed her. However, in SPORT TDM mode, the AD1836 can only generate a 48 kHz sample
rate. 96 kHz is only supported in the AD1836's I2S modes. Therefore, the sample rate using the AD1836/21161 EZ-KIT
lite driver is limited to 48 kHz.
The AD1836's TDM mode interface incorporates a 4 pin digital serial interface that links it to the ADSP-21161. The pins
assigned to the AD1836 are: ALRCLK, ABCLK, ASDATA1, and DSDATA1.
communicated over this point to point serial interconnection to the DSP, while all command/status information is
communicated over the slave SPI-compatible interface. A breakout of the signals connecting the two is shown in Figure 8. For
a detailed description of the TDM serial protocol between the DSP and the AD1836, the reader can refer to the next section.
Figure 8. AD1836 Interconnection To The ADSP-21161 DSP's SPORTs 0/2 pair, and it's SPI-Compatible Port
The AD1836's TDM mode defines digital serial connection which is a bi-directional, fixed rate, serial PCM digital stream.
The ADSP-21161 handles multiple input and output audio streams employing a time-division-multiplexed (TDM) scheme. The
AD1836's TDM architecture divides each audio frame into 8 outgoing and 8 incoming data streams, each with 24-bit sample
resolution contained within the 32-bit timeslot. This TDM approach allows low DSP software overhead to transmit and receive
data and thus enables a more simplified interface to the ADSP-21161 DSP.
ADSP-21161
TDM Interface
SPI Interface
SPORT0/2
SPICLK
SCLK0
SCLK2
FLAG0
MOSI
MISO
FS0
D0A
D2A
FS2
CCLK
CLATCH
CDATA
COUT
All digital audio data information is
ALRCLK
ABCLK
ASDATA1
DSDATA1
AD1836
No discussion covering an I
Extended TDM
Serial Interface
AD1836 SPI
Control Port
Interface
2
S