Advanced Information
WM8753L
OUTPUT MIXERS
The WM8753L provides the option to mix the Hi-FI DAC output signals and Voice DAC output signal
with analogue line-in signals from the bypass and sidetone paths. The level of the mixed-in signals
can be controlled with PGAs (Programmable Gain Amplifiers). The Mono mixer has a gain of -6dB to
allow two signals with input amplitude of 0dB to be mixed together without clipping. This may be
compensated for using the output PGAs if required.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
00
DESCRIPTION
Line Mix Select:
R47 (2Fh)
Input Control (1)
LMSEL[1:0]
[4:3]
00: LINE1 + LINE2
01: LINE1 – LINE2
10: LINE1 (LINE2 disconnected)
11: LINE2 (LINE1 disconnected)
MM
RM
LM
0
0
0
Mono Mux Select
0 : Line Mix Output
1: Rx Mix output ( RXP +/– RXN )
2
1
0
Right Mux Select
0 : LINE2
1 : Rx Mix output ( RXP +/– RXN )
Left Mux Select
0 : LINE1
1 : Rx Mix output ( RXP +/– RXN )
Table 30 Analogue Input to Output Mixer Bypass Signal Selection (same as Table 4)
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
00
DESCRIPTION
R48 (30h)
Input Control (2)
RXMSEL[1:0]
Differential input, Rx, mixer
00: RXP – RXN
[7:6]
01: RXP + RXN
10: RXP (RXN disconnected)
11: RXN (RXP disconnected)
MICMUX[1:0]
00
Mic Mux Sidetone Select
[5:4]
00 : Sidetone = Left PGA output
01 : Sidetone = Mic1 preamp output
10 : Sidetone = Mic 2 preamp output
11 : Sidetone = Right PGA output
LINEALC
MIC2ALC
MIC1ALC
RXALC
0
0
0
0
ALC Mix input select Line Mix
0 : Line Mix not selected into ALC Mix
1 : Line Mix selected into ALC Mix
3
2
1
0
ALC Mix input select MIC2
0 : MIC2 not selected into ALC Mix
1 : MIC2 selected into ALC Mix
ALC Mix input select MIC1
0 : MIC1 not selected into ALC Mix
1 : MIC1 selected into ALC Mix
ALC Mix input select RX
0 : RX not selected into ALC Mix
1 : RX selected into ALC Mix
Table 31 Analogue input to output Mixers Sidetone Signal Selection
AI Rev 3.1 June 2004
40
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
