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Channel Status Information (PCM2902)

Copyright Management (PCM2902)

INTERFACE SEQUENCE

Power On, Attach, and Playback Sequence

D+/D–

2.5V(Typ)

0V

InternalReset

ReadyforSetup

SOF

ReadyforPlayback

BusReset

SetConfiguration

SOF

SOF

BPZ

BusIdle

5V (Typ)

1 AudioData

st

2

AudioData

nd

V

(Pin3)

BUS

SSPND

V

L

OUT

V

R

OUT

700 s

m

DeviceSetup

1ms

T0055-02

PCM2900

PCM2902

SLES035E – MARCH 2007 – REVISED MARCH 2008

The channel status information is fixed as consumer application, PCM mode, copyright, and digital/digital

converter. All other bits are fixed as 0s except for the sample frequency, which is set automatically according to

the data received through the USB.

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.

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.

Figure 32. Initial Sequence

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Product Folder Link(s): PCM2900 PCM2902