Asynchronous Sample Rate Converter for the Cortex M3 and Cortex M4

The ARM Cortex M3 and Cortex M4 are new entrants to the audio design processing possibilities.  ARM contracted with DSP Concepts to provide DSP library for their Cortex-M family.  Because we specialize in audio DSP and have served the world’s most prestigious customers for over a decade, we understand what’s needed for audio product developers.   DSP Concepts now also offers a patent pending Asynchronous Sample Rate Converter (ASRC) for the M3 and M4.  Unlike other Asynchronous Sample Rate Converters which are one size fit all.  DSP Concepts’ Asynchronous Sample Rate Converter offers tunable customized coefficients to suit any specific Signal to Noise Ratio (SNR) requirements.  On top of this customization feature, this Asynchronous Sample Rate Converter is optimized to perform using the lowest MIPS and memory size in the industry.

Asynchronous Sample Rate Converter algorithms are particularly tricky to implement for audio applications.  It takes substantial experience in audio DSP to know that it involves taking a certain amount of extra samples so that you don’t get bad artifacts during that conversion process.  Some of this is not apparent until the Sample Rate Converter is put into audio applications.  The wrong interpolations in the Sample Rate Converter can negatively affect the clarity in the higher bands and cause poor imaging issues in sound quality.

Cortex M3 and M4 have just recently been designed into ST, Freescale, and NXP microcontrollers and have just recently become available to audio OEMs.  Many audio product makers are still trying to find a way of using these microcontrollers for such applications that have been traditionally given to DSPs.  Unfortunately for microcontrollers, they don’t come with ready audio design tools to help engineers implement audio DSP designs.  This is where DSP Concepts repeatedly wins out on the speed of product development for our clients.  Our DSP library, our Asynchronous Sample Rate Converter, and our proprietary audio design tool work in conjunction to speed up the development process.  

I will talk on another post about the secret weapon that enables our customers to go from concept to design to product in 1/5 of the normal development time.