WM8720_05 Datasheet, PDF (12/17 Pages) Wolfson Microelectronics plc – 24-bit, 96kHz Stereo DAC with Volume Control

WM8720
REGISTER MAP
Production Data
WM8720 controls the special functions using 4 program registers, which are 16-bits long. These
registers are all loaded through input pin MD/DM. After the 16 data bits are clocked in, ML/I2S/IWL is
used to latch in the data to the appropriate register. Table 7 shows the complete mapping of the
4 registers.
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
M0 --
-
-
-
-
A1 A0 LDL AL7 AL6 AL5 AL4 AL3 AL2 AL1 AL0
M1 -
-
-
-
-
A1 A0 LDR AR7 AR6 AR5 AR4 AR3 AR2 AR1 AR0
M2 -
-
-
-
-
A1 A0 PL3 PL2 PL1 PL0 IW1 IW0 OPE DE MU
M3 -
-
-
-
-
A1 A0 IZD SF1 SF0 -
-
- ATC LRP I²S
Table 7 Mapping of Program Registers
REGISTER NAME
Register 0 (M0)
A[1:0] = 00
Register 1 (M1)
A[1:0] = 01
Register 2 (M2)
A[1:0] = 10
Register 3 (M3)
A[1:0] = 11
BIT NAME
AL[7:0]
LDL
AR[7:0]
LDR
MU
DE
OPE
IW[1:0]
PL[3:0]
I²S
LRP
ATC
SF[1:0]
IZD
Table 8 Internal Register Mapping
DEFAULT
1111 1111
0
1111 1111
0
0
0
0
00
1001
0
0
0
00
0
DESCRIPTION
DAC attenuation data for left channel
Attenuation data load control for left channel
DAC attenuation data for right channel
Attenuation data load control for right channel
Left and right DACs soft mute control
De-emphasis control
Left and right DACs operation control
Input audio word resolution
DAC output control
Audio data format select
Polarity of LRCIN (pin 7) select
Attenuator control
Sampling rate select
Infinite zero detection circuit control and automute control
DAC OUTPUT ATTENUATION
Register 0 (A[1:0] = 00) is used to control left channel attenuation. Bits 0-7 (AL[7:0]) are used to
determine the attenuation level Table 9. The level of attenuation is given by:
Attenuation = [20.log10 (Attenuation_Data/256)] dB ................................................................................................... Eqn. 1
w
PD Rev 4.0 February 2005
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