AN1836-AN21161 Analog Devices, AN1836-AN21161 Datasheet - Page 3

• 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

0.1 ADSP-2161 EZ-KIT Lite: An AD1836/ADSP-21161 Audio System Reference Design
The AD1836/ADSP-21161 pairing satisfies the higher fidelity audio requirements for new emerging audio applications, and
offers many advantages for a low-cost high-fidelity audio platform, including:
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AD1836's TDM Serial Mode enables DSP Serial Port Multichannel Mode (TDM) Compatibility.
This mode enables a protocol where each TDM (time-division multiplexed) frame sync generates 8 timeslots which are 32-
bits per slot, allowing a much easier interface to 32-bit DSPs that support a TDM interface. The TDM approach allows the
use of serial port 'autobuffering' or 'DMA chaining' along with the ADSP-21xxx Serial Port Multichannel Mode (TDM)
operation. The AD1836 TDM interface also allows the DSP system designer to require the use of 1 TDM serial port pair,
saving the use of an additional serial port. For example, on the ADSP-21161, 3 SPORTs would be necessary to be able to
communicate with the AD1836's 2 stereo I
Sampling Rate support for 24-bit, 48/96 kHz
The AD1836 can generate sample rates of 48 kHz and 96 kHz, enabling the capability to record and play back higher
quality audio. Recent studies in human hearing indicate that 16-bit CD-quality audio does not suffice for high-fidelity
audio, and at least 24-bit/96kHz processing is required.
High Quality 105 dB Dynamic Range and Signal to Noise Ratio on the ADCs and DACs
Surpassing the 'CD-Quality' sound offered by 16-bit conversion (96 dB maximum), the ability to maintain 105 dB
approaches signal quality typically found only in expensive professional audio systems.
32-bit SIMD Fixed Point, or 32/40-bit Floating Point Audio Processing of 24-bit digitized signals at 600 Mflops Peak,
400 Mflops sustained performance
The ADSP-21161's SIMD (single-instruction, multiple-data) architecture enables multichannel processing of audio signals
simultaneously via 2 identical computation units, providing the ability to maintain the 24-bit signal integrity by ensuring
that any quantization errors produced during arithmetic operations are lower than the 105 dB noise floor of the AD1836
ADCs and DACs.
Figure 2. 21161 EZ-KIT Lite / AD1836 Audio Development System
2
S ADCs and 3 stereo I
2
S DACs.