The PCM2906C datasheet states (on page 21) quote:
Copyright ManagementIsochronous-in data are affected by the serial copy management system (SCMS). When the control bit indicatesthat the received digital audio data are original, the input digital audio data are transferred to the host. If the dataare indicated as first generation or higher, the transferred data are routed to the analog input.
Does this mean that inbound USB Isochronous-in data (i.e. USB data from the Host PC to the PCM2906) if indicated as 1st generation copy will be routed to the analog input of the PCM2906. How can this be? Surely that is an analog signal input, not an output. I'd like a clearer description, and specifically in terms of the SPDIF data paths. Is there a more in-depth document available than this poorly worded section.
Hi, Steve,
We're looking to clarify this for you.
-d2
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Don Dapkus
Audio Applications Engineering Manager
Dallas, TX USA
Thanks d2.
-Steve
Steve,
SCMS ensures digital copyright protection. Essentially, the part will not allow for transfer of copyrighted data to the host via recording. So if the copyright bit is present, (data indicated as first-generation or higher), the only viable means of recording will be through the ADC, with analog input as opposed to digital input.
Patrick Galvin