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.
t
MHH
ML
t
MLS
MC
t
MCY
LSB
MD
t
MDS
t
MCH
50% of V
DD
t
MCH
t
MCL
t
MLH
50% of V
DD
50% of V
DD
SYMBOL
t
MCY
t
MCL
t
MCH
t
MHH
t
MLS
t
MLH
t
MDH
t
MDS
PARAMETER
MC Pulse Cycle Time
MC Low Level Time
MC High Level Time
ML High Level Time
ML Falling Edge to MC Rising Edge
ML Hold Time
(1)
MD Hold Time
MD Set Up Time
MIN
100
50
50
Note (2)
20
20
15
20
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
3
NOTES: (1) MC rising edge for LSB to ML rising edge. (2)
256
•
f
sec (min), f
S
= Sampling Rate.
S
FIGURE 7. Control Interface Timing.
FUNCTION
RESET DEFAULT
CONTROL REGISTER
INDEX, IDX[6:0]
Digital Attenuation Control, 0dB to –63dB in 0.5dB Steps
Soft Mute Control
Oversampling Rate Control (64 or 128f
S
)
DAC Operation Control
De-Emphasis Function Control
De-Emphasis Sample Rate Selection
Audio Data Format Control
Digital Filter Roll-Off Control
Zero Flag Function Select
Output Phase Select
Zero Flag Polarity Select
0dB, No Attenuation
Mute Disabled
64f
S
Oversampling
DAC1 and DAC2 Enabled
De-Emphasis Disabled
44.1kHz
24-Bit Left Justified
Sharp Roll-Off
L-/R-Channel Independent
Normal Phase
High
16 and 17
18
18
19
19
19
20
20
22
22
22
AT1[7:0], AT2[7:0]
MUT[2:0]
OVER
DAC[2:1]
DM12
DMF[1:0]
FMT[2:0]
FLT
AZRO
DREV
ZREV
TABLE II. User-Programmable Mode Controls.
IDX
(B8-B14) REGISTER
10
H
11
H
12
H
13
H
14
H
15
H
16
H
16
17
18
19
20
21
22
B15
0
0
0
0
0
0
0
B14
IDX6
IDX6
IDX6
IDX6
IDX6
IDX6
IDX6
B13
IDX5
IDX5
IDX5
IDX5
IDX5
IDX5
IDX5
B12
IDX4
IDX4
IDX4
IDX4
IDX4
IDX4
IDX4
B11
IDX3
IDX3
IDX3
IDX3
IDX3
IDX3
IDX3
B10
IDX2
IDX2
IDX2
IDX2
IDX2
IDX2
IDX2
B9
IDX1
IDX1
IDX1
IDX1
IDX1
IDX1
IDX1
B8
IDX0
IDX0
IDX0
IDX0
IDX0
IDX0
IDX0
B7
AT17
AT27
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
B6
AT16
AT26
OVER
DMF1
RSV
(1)
RSV
(1)
RSV
(1)
B5
AT15
AT25
RSV
(1)
DMF0
FLT
RSV
(1)
RSV
(1)
B4
AT14
AT24
RSV
(1)
DM12
RSV
(1)
RSV
(1)
RSV
(1)
B3
AT13
AT23
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
RSV
(1)
B2
B1
B0
AT12 AT11 AT10
AT22 AT21 AT20
RSV
(1)
MUT2 MUT1
RSV
(1)
DAC2 DAC1
FMT2 FMT1 FMT0
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.
TABLE III. Mode Control Register Map.
PCM1741
SBAS175
11
BURR-BROWN [ BURR-BROWN CORPORATION ]
