Datasheet
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PCM1774
SLAS551 – JULY 2007
Registers 68 and 69
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Register 68 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV PMUL ATL5 ATL4 ATL3 ATL2 ATL1 ATL0
Register 69 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV PMUR ATR5 ATR4 ATR3 ATR2 ATR1 ATR0
IDX[6:0]: 100 0100b (44h): Register 68
IDX[6:0]: 100 0101b (45h): Register 69
PMUL: Digital Soft Mute Control for DAL (DAC L-Channel)
PMUR: Digital Soft Mute Control for DAR (DAC R-Channel)
Default value: 0
The digital inputs of the DAC can be independently muted by setting PMUL and PMUR = 1. The digital data is
changed from the current attenuation level to mute level by a 1-dB step for every 8/f
S
time period. When PMUL
and PMUR are set to 0, the digital data is changed from the mute level to the current attenuation level by a 1-dB
step for every 8/f
S
time period. In the PCM1774, audible zipper noise can be reduced by selecting zero-cross
detection (register 86, ZCRS).
PMUL, PMUR = 0 Mute disabled (default)
PMUL, PMUR = 1 Mute enabled
ATL[5:0]: Digital Attenuation Setting for DAL (DAC L-Channel)
ATR[5:0]: Digital Attenuation Setting for DAR (DAC R-Channel)
Default value: 11 1111b
The digital inputs of the DAC can be independently attenuated. The attenuation of the digital input is changed by
a 1-dB step for every 8/f
S
time period. Audible zipper noise in the PCM1774 can be reduced by selecting
zero-cross detection (register 86, ZCRS).
Table 8. Digital Attenuation Setting
ATL[5:0], ATTENUATION LEVEL ATL[5:0], ATTENUATION LEVEL ATL[5:0], ATTENUATION LEVEL
ATR[5:0] SETTING ATR[5:0] SETTING ATR[5:0] SETTING
11 1111 3F 0 dB (default) 10 1001 29 –22 dB 01 0011 13 –44 dB
11 1110 3E –1 dB 10 1000 28 –23 dB 01 0010 12 –45 dB
11 1101 3D –2 dB 10 0111 27 –24 dB 01 0001 11 –46 dB
11 1100 3C –3 dB 10 0110 26 –25 dB 01 0000 10 –47 dB
11 1011 3B –4 dB 10 0101 25 –26 dB 00 1111 0F –48 dB
11 1010 3A –5 dB 10 0100 24 –27 dB 00 1110 0E –49 dB
11 1001 39 –6 dB 10 0011 23 –28 dB 00 1101 0D –50 dB
11 1000 38 –7 dB 10 0010 22 –29 dB 00 1100 0C –51 dB
11 0111 37 –8 dB 10 0001 21 –30 dB 00 1011 0B –52 dB
11 0110 36 –9 dB 10 0000 20 –31 dB 00 1010 0A –53 dB
11 0101 35 –10 dB 01 1111 1F –32 dB 00 1001 09 –54 dB
11 0100 34 –11 dB 01 1110 1E –33 dB 00 1000 08 –55 dB
11 0011 33 –12 dB 01 1101 1D –34 dB 00 0111 07 –56 dB
11 0010 32 –13 dB 01 1100 1C –35 dB 00 0110 06 –57 dB
11 0001 31 –14 dB 01 1011 1B –36 dB 00 0101 05 –58 dB
11 0000 30 –15 dB 01 1010 1A –37 dB 00 0100 04 –59 dB
10 1111 2F –16 dB 01 1001 19 –38 dB 00 0011 03 –60 dB
10 1110 2E –17 dB 01 1000 18 –39 dB 00 0010 02 –61 dB
10 1101 2D –18 dB 01 0111 17 –40 dB 00 0001 01 –62 dB
10 1100 2C –19 dB 01 0110 16 –41 dB 00 0000 00 Mute
10 1011 2B –20 dB 01 0101 15 –42 dB
10 1010 2A –21 dB 01 0100 14 –43 dB
25
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