Datasheet
SLES101A – DECEMBER 2003 – REVISED NOVEMBER 2006
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22
Register Map
The mode control register map is shown in Table 3. Registers 16–21 include an R/W bit, which determines whether a
register read (R/W
= 1) or write (R/W = 0) operation is performed. Registers 22 and 23 are read-only.
Table 3. Mode Control Register Map
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Register 16 R/W 0 0 1 0 0 0 0 ATL7 ATL6 ATL5 ATL4 ATL3 ATL2 ATL1 ATL0
Register 17 R/W 0 0 1 0 0 0 1 ATR7 ATR6 ATR5 ATR4 ATR3 ATR2 ATR1 ATR0
Register 18 R/W 0 0 1 0 0 1 0 ATLD FMT2 FMT1 FMT0 DMF1 DMF0 DME MUTE
Register 19 R/W 0 0 1 0 0 1 1 REV ATS1 ATS0 OPE ZOE DFMS FLT INZD
Register 20 R/W 0 0 1 0 1 0 0 RSV SRST DSD DFTH MONO CHSL OS1 OS0
Register 21 R/W 0 0 1 0 1 0 1 RSV RSV RSV RSV RSV DZ1 DZ0 PCMZ
Register 22 R 0 0 1 0 1 1 0 RSV RSV RSV RSV RSV RSV ZFGR ZFGL
Register 23 R 0 0 1 0 1 1 1 RSV RSV RSV ID4 ID3 ID2 ID1 ID0
Register Definitions
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Register 16 R/W 0 0 1 0 0 0 0 ATL7 ATL6 ATL5 ATL4 ATL3 ATL2 ATL1 ATL0
Register 17 R/W 0 0 1 0 0 0 1 ATR7 ATR6 ATR5 ATR4 ATR3 ATR2 ATR1 ATR0
R/W: Read/Write Mode Select
When R/W = 0, a write operation is performed.
When R/W = 1, a read operation is performed.
Default value: 0
ATx[7:0]: Digital Attenuation Level Setting
These bits are available for read and write.
Default value: 1111 1111b
Each DAC output has a digital attenuator associated with it. The attenuator can be set from 0 dB to –120 dB, in 0.5-dB steps.
Alternatively, the attenuator can be set to infinite attenuation (or mute).
The attenuation data for each channel can be set individually. However, the data load control (the ATLD bit of control register
18) is common to both attenuators. ATLD must be set to 1 in order to change an attenuator setting. The attenuation level
can be set using the following formula:
Attenuation level (dB) = 0.5 dB • (ATx[7:0]
DEC
– 255)
where ATx[7:0]
DEC
= 0 through 255
For ATx[7:0]
DEC
= 0 through 14, the attenuator is set to infinite attenuation. The following table shows attenuation levels
for various settings:
ATx[7:0] Decimal Value Attenuation Level Setting
1111 1111b 255 0 dB, no attenuation (default)
1111 1110b 254 –0.5 dB
1111 1101b 253 –1.0 dB
L LL
0001 0000b 16 –119.5 dB
0000 1111b 15 –120.0 dB
0000 1110b 14 Mute
L LL
0000 0000b 0 Mute