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AMIC110: Broad selection for High-speed USB Audio Class Device processor

Brian Willoughby
Genius 4640 points

Part Number: AMIC110
Other Parts Discussed in Thread: TMS320VC5506

I would like help selecting a processor from the Texas Instruments catalog that meets my needs, but I am not currently sure whether this needs to be a DSP or ARM or other processor.

In the past, I have completed designs using the TMS320VC5506, TM4C129E, and MSP430. Each of those enjoyed good support, and I would be open to using any family of processor so long as it has the interface pins needed.

Before listing peripheral requirements, I would like to state that I prefer plastic quad flatpack packaging to keep the PCB layout and fabrication easy. I know that the TMS320 is available in PQFP, but it was difficult to find High-speed USB Device support in that type of package.

USB Audio Class Device requirements are 16 output channels at 24-bit 192kHz (Host to Device); support for 96kHz and 48kHz; some number of input channels (Device to Host); nice-to-have features would be 32 channels at 96k and up to 64 channels at 48k. Particularly nice would be a processor with USB Audio Class Device firmware that has been tested with 16 channels at 192 kHz in at least the output-only direction. That's at least 74Mbps or 9.3 MB/s.

Other port requirements are 32-bit TDM with 2 data lines in each direction, and 8 channels per data for 16 channels total at 192 kHz. Again, support for 96k and 48k with increased channel count in proportion to the sample rate reduction. This would be 49.152 Mbps on each data line, 2 in / 2 out, or 12.288 MB/s total in each direction. Both McBSP and McASP peripherals will probably suffice for this.

The final feature is connection(s) to 16 channels of 24-bit or 32-bit ADC at 192 kHz. Support for 96k and 48k is needed, but no more than 16 channels. I believe that single ADC chips have a maximum of 8 channels (to my knowledge) so a couple of ports in parallel, or a McBSP/McASP with at least 2 data lines for input would be needed to interface to a couple of 8-channel ADC.

Nice to have features beyond the above would be a port for controlling an LCD, LED, or OLED display of some sort; and Ethernet 100BASE-TX or 1000BASE-T, but the Ethernet is particularly not a requirement.

Thank you. If you can narrow my search down to a particular family that has good options for the above, then I can probably use the Texas Instruments selection tools to pick a particular family member. I am mostly asking for help because it is difficult to search TMS320 DSP, ARM, and other processor families in the same grid.

Brian Willoughby

  • 0
    Genius 4640 points

    Some more information on requirements:

    In general, I prefer a single core processor, or at least a multi-core processor that can run from a single firmware image. The reason for this preference is that developing multiple firmware designs for a single product becomes difficult. Thus, if a TMS320 fits the needs listed above, then I would want to handle both USB and TDM (McASP) data streams in the same firmware source. Similarly, if a Sitara or Stellaris ARM processor has all of the I/O needed, then I would sacrifice the option for DSP processing of the data in exchange for keeping the firmware to one image.

    However, in this case, the display (LCD/LED/OLED) and Ethernet could easily be separated from the audio data streams, such that user interface and control are handled by one processor with its own firmware, while the USB and TDM audio streams are handled by a DSP or other, separate processor. For a clean split like this, there might be a benefit to having separate processors with separate firmware, and a very simple, low-bandwidth parameter communication channel between the two subsystems.

    I have heard about the Texas Instrument OMAP chips, which pair TMS320 and ARM, and those might be a good option. Unfortunately, they all see to be expensive, and thus may be overqualified for this task.

    I am also seeing a few processors with independent PRU (Programmable Real-Time Unit) cores, and it seems that these might be worth considering. But these are new to me, so I am not familiar with their use cases.

    To summarize: My search preference is for a single processor that can handle everything. If relegating the display and Ethernet to a second processor helps find a PQFP package DSP that can handle High-speed USB and TDM, that would be a good option, especially if the second processor is in the same chip.