PCM2900

PCM2902

SLES035B − MARCH 2002 − REVISED JUNE 2004

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Copyright Management (PCM2902)

Isochronous-in data is affected by the serial copy management system (SCMS). Where receiving digital audio

data that is indicated as original data in the control bit, input digital audio data transfers to the host. If the data

is indicated as first generation or higher, transferred data is selected to analog input.

Digital audio data output is always encoded as original with SCMS control.

The implementation of this feature is an option for the customer. Note that it is the user’s responsibility whether

they implement this feature in their product or not.

INTERFACE SEQUENCE

Power On, Attach, and Playback Sequence

The PCM2900/2902 is ready for setup when the reset sequence has finished and the USB bus is attached. After

connection has been established by setup, the PCM2900/2902 is ready to accept USB audio data. While

waiting, the audio data (idle state) and analog output are set to bipolar zero (BPZ).

When receiving the audio data, the PCM2900/2902 stores the first audio packet, which contained 1-ms audio

data, into the internal storage buffer. The PCM2900/2902 starts playing the audio data when detecting the

following start of frame (SOF) packet.

D+/D−

2.5 V (Typ.)

0 V

Internal Reset

Ready for Setup

SOF

Ready for Playback

Bus Reset

Set Configuration

SOF

SOF

BPZ

Bus Idle

5 V

(Typ.)

1st Audio Data

2nd Audio Data

VBUS (Pin 3)

SSPND

VOUTL

VOUTR

700

µs

Device Setup

1 ms

Figure 32. Initial Sequence

Play, Stop, and Detach Sequence

When the host finishes or aborts the playback, the PCM2900/2902 stops playing after the last audio data has

played.

Record Sequence

The PCM2900/2902 starts the audio capture into the internal memory after receiving the SET_INTERFACE

command.