Datasheet
PCM1741
11
SBAS175
MODE CONTROL REGISTERS
User-Programmable Mode Controls
The PCM1741 includes a number of user-programmable
functions that are accessed via control registers. The regis-
ters are programmed using the Serial Control Interface that
was previously discussed in the “Serial Control Interface”
section of this data sheet. Table II lists the available mode
control functions, along with their reset default conditions
and associated register index.
Register Map
The mode control register map is shown in Table III. Each
register includes an index (or address) indicated by the
IDX[6:0] bits.
FUNCTION RESET DEFAULT CONTROL REGISTER INDEX, IDX[6:0]
Digital Attenuation Control, 0dB to –63dB in 0.5dB Steps 0dB, No Attenuation 16 and 17 AT1[7:0], AT2[7:0]
Soft Mute Control Mute Disabled 18 MUT[2:0]
Oversampling Rate Control (64 or 128f
S
) 64f
S
Oversampling 18 OVER
DAC Operation Control DAC1 and DAC2 Enabled 19 DAC[2:1]
De-Emphasis Function Control De-Emphasis Disabled 19 DM12
De-Emphasis Sample Rate Selection 44.1kHz 19 DMF[1:0]
Audio Data Format Control 24-Bit Left Justified 20 FMT[2:0]
Digital Filter Roll-Off Control Sharp Roll-Off 20 FLT
Zero Flag Function Select L-/R-Channel Independent 22 AZRO
Output Phase Select Normal Phase 22 DREV
Zero Flag Polarity Select High 22 ZREV
TABLE II. User-Programmable Mode Controls.
TABLE III. Mode Control Register Map.
IDX
(B8-B14) REGISTER B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
10
H
16 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 AT17 AT16 AT15 AT14 AT13 AT12 AT11 AT10
11
H
17 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 AT27 AT26 AT25 AT24 AT23 AT22 AT21 AT20
12
H
18 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV
(1)
OVER RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
MUT2 MUT1
13
H
19 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV
(1)
DMF1 DMF0 DM12 RSV
(1)
RSV
(1)
DAC2 DAC1
14
H
20 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV
(1)
RSV
(1)
FLT RSV
(1)
RSV
(1)
FMT2 FMT1 FMT0
15
H
21 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
16
H
22 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
AZRO ZREV DREV
NOTE: (1) RSV = Reserved for test operation. It should be set to “0” when in regular operation.
SYMBOL PARAMETER MIN TYP MAX UNITS
t
MCY
MC Pulse Cycle Time 100 ns
t
MCL
MC Low Level Time 50 ns
t
MCH
MC High Level Time 50 ns
t
MHH
ML High Level Time Note (2) ns
t
MLS
ML Falling Edge to MC Rising Edge 20 ns
t
MLH
ML Hold Time
(1)
20 ns
t
MDH
MD Hold Time 15 ns
t
MDS
MD Set Up Time 20 ns
NOTES: (1) MC rising edge for LSB to ML rising edge. (2)
3
256 • f
S
sec (min), f
S
= Sampling Rate.
FIGURE 7. Control Interface Timing.
50% of V
DD
50% of V
DD
50% of V
DD
ML
MC
MD
t
MLS
t
MCH
t
MCY
t
MDS
t
MCH
t
MCL
t
MHH
t
MLH
LSB