Audio Sample Rate Converter, Low Cost

"The CWda50 is a low cost configurable Mono/Stereo asynchronous Audio Sample Rate Converter (ASRC). This core can be used to solve the problem of interfacing digital audio equipment operating at different sample rates. It has been designed for systems requiring moderate quality in terms of harmonic distortion and noise: it can realize most common sample rate conversions at -70 dB of Total Harmonic Distortion plus Noise (THD+N), while requiring very few logic resources. On an FPGA, it is ideal to convert between low audio sample rates (in the range of 8-12Khz) using reasonable master clock frequencies. In the mono version (CWda50m), the required logic resources almost halves. The CWda50 uses the Coreworks Audio Parallel Interface for the input audio data, which permits bridging to other slave interfaces: I2S, SPDIF-AES/EBU, AMBA, PowerPC (CoreConnect â„¢). At the output it also features a slave I2S audio interface: the user supplies the i2s_sclk and i2s_lrclk signals and recei! ves back the i2s_sdata signal; this allows connection to a master I2S device.

Device Family Support
# Virtex-4 FX
# Virtex-4 LX
# Virtex-4 SX
# Virtex-II Pro
# Spartan-3L
# Spartan-3E
# Spartan-3
# Spartan-IIE

Key Features
# Stereo (CWda50s) and Mono (CWda50m) versions.
# -70dB THD+N for common conversion rates.
# 83 dB Dynamic Range for common conversion rates.
# Fully digital solution with 14-bit input.
# Additional I2S slave audio interface.
# Converts asynchronously between low sample rates in the 8-12 KHz range on low cost FPGAs.
# Very low use of logic resources."