Datasheet

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Register Definitions
PCM1770 , PCM1771
SLES011E – SEPTEMBER 2001 – REVISED MARCH 2007
Register 01
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 MUTR MUTL ATL5 ATL4 ATL3 ATL2 ATL1 ATL0
IDX[6:0]: 000 0001b
MUTx: Soft Mute Control
Where, x = L or R, corresponding to the headphone output H
OUT
L or H
OUT
R.
Default value: 0
MUTL, MUTR = 0 Mute disabled (default)
MUTL, MUTR = 1 Mute enabled
The mute bits, MUTL and MUTR, enable or disable the soft mute function for the corresponding headphone
outputs, H
OUT
L and H
OUT
R. The soft mute function is incorporated into the digital attenuators. When mute is
disabled (MUTx = 0), the attenuator and DAC operate normally. When mute is enabled by setting MUTx = 1, the
digital attenuator for the corresponding output is decreased from the current setting to the infinite attenuation,
one attenuator step (1 dB) at a time. This provides pop-free muting of the headphone output.
By setting MUTx = 0, the attenuator is increased one step at a time to the previously programmed attenuation
level.
ATL[5:0]: Digital Attenuation Level Setting for Headphone Output, H
OUT
L
Default value: 11 1111b
Headphone output H
OUT
L includes a digital attenuation function. The attenuation level can be set from 0 dB to
–62 dB, in 1-dB steps. Changes in attenuator levels are made by incrementing or decrementing by one step (1
dB) for every 8/f
S
time internal until the programmed attenuator setting is reached. Alternatively, the attenuation
level may be set to infinite attenuation (or mute).
The following table shows the attenuation levels for various settings:
ATL[5:0] ATTENUATION LEVEL SETTING
11 1111b 0 dB, no attenuation (default)
11 1110b –1 dB
11 1101b –2 dB
: :
00 0010b –61 dB
00 0001b –62 dB
00 0000b Mute
Register 02
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV RSV ATR5 ATR4 ATR3 ATR2 ATR1 ATR0
IDX[6:0]: 000 0010b
ATR[5:0]: Digital Attenuation Level Setting for Headphone Output, H
OUT
R
Default value: 11 1111b
Headphone output H
OUT
R includes a digital attenuation function. The attenuation level can be set from 0 dB to
–62 dB, in 1-dB steps. Changes in attenuator levels are made by incrementing or decrementing by one step (1
dB) for every 8/f
S
time internal until the programmed attenuator setting in reached. Alternatively, the attenuation
level can be set to infinite attenuation (or mute).
To set the attenuation levels for ATR[5:0], see the table for ATL[5:0], register 01.
25
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