PCM1795 datasheet(48/58 Pages) TI

48 / 58 page

58BCKs

CommandField

DID

LRCK

BCK

DCO1,

DCI2

DeviceID=1

DeviceID=2

DCO1

DCO2,

DCI3

DCO29,

DCI30

DeviceID=3

DeviceID=30

TDMCA Frame

LRCK

BCK

CMD

EMD

CMD

Don’t

Care

EMD

Ch1

Ch(m)

Ch2

CMD

Ch2

Ch3

Ch(n)

CMD

Ch1

Ch4

Ch3

Ch4

[ForInitialization]

[ForOperation]

32Bits

CMD

1/f

Don’t

Care

PCM1795

SLES248 – MAY 2009 ........................................................................................................................................................................................................ www.ti.com

Figure 64. Device ID Determination Sequence

In general, the TDMCA frame consists of the command field, extended command (EMD) field, and audio data

fields. All fields are 32 bits in length, but the lowest byte has no meaning. The MSB is transferred first for each

field. The command field is always transferred as the first packet of the frame. The EMD field is transferred if the

EMD flag of the command field is high. If any EMD packets are transferred, no audio data follow the EMD

packets. This frame is for quick system initialization. All devices of a daisy-chain should respond to the command

field and extended command field. The PCM1795 has two audio channels that can be selected by OPE (register

19). If the OPE bit is not set to high, those audio channels are transferred. Figure 65 shows the general TDMCA

frame. If some DACs are enabled, but corresponding audio data packets are not transferred, the analog outputs

are unpredictable.

Figure 65. General TDMCA Frame

Submit Documentation Feedback

Product Folder Link(s): PCM1795

PCM1795 Datasheet(PDF) 48 Page - Texas Instruments

PCM1795 Datasheet(HTML) 48 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58

Datasheet Download

Link URL