wm8903 Wolfson Microelectronics plc, wm8903 Datasheet - Page 57

• Manufacturer Part Number: wm8903
• Description: Ultra Low Power Codec For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

Pre-Production
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OUTPUT SIGNAL PATHS ENABLE
Each output pin and each mixer can be independently enabled and disabled as shown in Table 35.
Note that the Headphone Outputs and Line Outputs are also controlled by fields located within
Register R90 and R94, which provide suppression of pops & clicks when enabling and disabling
these signal paths. These outputs cannot be fully enabled without the appropriate write operations to
Registers R90 and R94. See Pop Suppression Control” for details of these registers.
Under recommended usage conditions, all the control bits associated with enabling the Headphone
Outputs and the Line Outputs will be configured by running the default Start-Up and Shut-Down
sequences as described in the “Control Write Sequencer” section. In these cases, the user does not
need to set the register fields in R13, R14, R15, R90 and R94 directly.
Table 35 Output Signal Paths Enable
To enable the output PGAs and mixers, the reference voltage VMID and the bias current must also
be enabled. See “Reference Voltages and Master Bias” for details of the associated controls
VMID_RES and BIAS_ENA.
R13 (0Dh)
Power
Management 1
R14 (0Eh)
Power
Management 2
R15 (0Fh)
Power
Management 3
R16 (10h)
Power
Management 4
R17 (11h)
Power
Management 5
REGISTER
ADDRESS
BIT
1
0
1
0
1
0
1
0
1
0
MIXOUTL_ENA
MIXOUTR_ENA
HPL_PGA_ENA
HPR_PGA_ENA
LINEOUTL_PGA_
ENA
LINEOUTR_PGA
_ENA
MIXSPKL_ENA
MIXSPKR_ENA
SPKL_ENA
SPKR_ENA
LABEL
DEFAULT
0
0
0
0
0
0
0
0
0
0
Left Output Mixer Enable
0 = disabled
1 = enabled
Right Output Mixer Enable
0 = disabled
1 = enabled
Left Headphone Output Enable
0 = disabled
1 = enabled
Right Headphone Output Enable
0 = disabled
1 = enabled
Left Line Output Enable
0 = disabled
1 = enabled
Right Line Output Enable
0 = disabled
1 = enabled
Left Speaker Mixer Enable
0 = disabled
1 = enabled
Right Speaker Mixer Enable
0 = disabled
1 = enabled
Left Speaker Output Enable
0 = disabled
1 = enabled
Right Speaker Output Enable
0 = disabled
1 = enabled
PP, Rev 3.1, August 2009
DESCRIPTION
WM8903
57