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 128fS)

64fS 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

10H

16

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

AT17

AT16

AT15

AT14

AT13

AT12

AT11

AT10

11H

17

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

AT27

AT26

AT25

AT24

AT23

AT22

AT21

AT20

12H

18

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

RSV(1)

OVER RSV(1)

RSV(1) RSV(1) RSV(1)

MUT2

MUT1

13H

19

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

RSV(1)

DMF1

DMF0

DM12 RSV(1) RSV(1)

DAC2

DAC1

14H

20

0

IDX6

IDX5

IDX4

IDX3

IDX2

IDX1

IDX0

RSV(1)

RSV(1)

FLT

RSV(1) RSV(1)

FMT2

FMT1

FMT0

15H

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)

16H

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

tMCY

MC Pulse Cycle Time

100

ns

tMCL

MC Low Level Time

50

ns

tMCH

MC High Level Time

50

ns

tMHH

ML High Level Time

Note (2)

ns

tMLS

ML Falling Edge to MC Rising Edge

20

ns

tMLH

ML Hold Time(1)

20

ns

tMDH

MD Hold Time

15

ns

tMDS

MD Set Up Time

20

ns

NOTES: (1) MC rising edge for LSB to ML rising edge. (2)

3

256

• f

S

sec (min), fS = 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