Datasheet
SLES105B − FEBRUARY 2004 − REVISED NOVEMBER 2006
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45
DSD MODE CONFIGURATION AND FUNCTION CONTROLS
Configuration for the DSD Interface Mode
DSD = 1 (Register 20, B5)
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Register 16 R/W 0 0 1 0 0 0 0 – – – – – – – –
Register 17 R/W 0 0 1 0 0 0 1 – – – – – – – –
Register 18 R/W 0 0 1 0 0 1 0 – – – – DMF1 DMF0 – –
Register 19 R/W 0 0 1 0 0 1 1 REV – – OPE – – – –
Register 20 R/W 0 0 1 0 1 0 0 – SRST 1 – MONO CHSL OS1 OS0
Register 21 R 0 0 1 0 1 0 1 – – – – – DZ1 DZ0 –
Register 22 R 0 0 1 0 1 1 0 – – – – – – ZFGR ZFGL
NOTE: –: Function is disabled. No operation even if data bit is set
DMF[1:0]: Analog FIR Performance Selection
Default value: 00
DMF[1:0] Analog-FIR Performance Select
00 FIR-1 (default)
01 FIR-2
10 FIR-3
11 FIR-4
Plots for the four analog FIR filter responses are shown in the TYPICAL PERFORMANCE CURVES section
of this data sheet.
OS[1:0]: Analog-FIR Operation-Speed Selection
Default value: 00
OS[1:0] Operation Speed Select
00 f
DBCK
(default)
01 f
DBCK
/2
10 Reserved
11 f
DBCK
/4
The OS bit in the DSD mode is used to select the operating rate of the analog FIR. The OS bits must be set
before setting the DSD bit to1.
TDMCA Format
The PCM1792A supports the time-division-multiplexed command and audio (TDMCA) data format to simplify
the host control serial interface. The TDMCA format is designed not only for the McBSP of TI DSPs but also
for any programmable devices. The TDMCA format can transfer not only audio data but also command data,
so that it can be used together with any kind of device that supports the TDMCA format. The TDMCA frame
consists of command field, extended command field, and some audio data fields. Those audio data are
transported to IN devices (such as a DAC) and/or from OUT devices (such as an ADC). The PCM1792A is an
IN device. LRCK and BCK are used with both IN and OUT devices so that the sample frequency of all devices
in a system must be the same. The TDMCA mode supports a maximum of 30 device IDs. The maximum number
of audio channels depends on the BCK frequency.