xwm8722eds ETC-unknow, xwm8722eds Datasheet - Page 20

• Manufacturer Part Number: xwm8722eds
• Description: Stereo Dac With Integrated Tone Generator And Line/variable Level Outputs
• Manufacturer: ETC-unknow

WM8722
REGISTER 12
REGISTER 13
Figure 9 Output Mixer Configuration
M6DB
In each of the 4 MUX control registers there is an M6DB bit relevant to that channel. Setting M6DB
high reduces the relevant output signal by 6dB.
BOTH
channel MXSEL register for the other channel is updated with the same value. For example, if
RVMXSEL is updated and BOTH is set, then LVMXSEL is updated with the same value, but the
RMXSEL and LMXSEL registers (the non variable output path muxes) are NOT updated.
TONE DURATION
Bits 0-7 of register 12 sets the duration of the tone burst. Writing to the register with a non-zero value
starts the tone burst. Wring zero to this register stops the tone.
T = (2.7x10
TONE GENERATOR GAIN CONTROL
Bits 0-4 of register 13 TVOL[0:4] set the gain level of the tones summed into the analogue outputs.
Bit 5 of this word controls muting of the tones. Note both mute must be off (0) and the tone input to
the relevant mixer summing path must be selected (1). The gain defaults to 0dB (11111) but may be
attenuated in 1.5dB steps down to –46.5dB.
TONE GENERATOR WAVEFORM CONTROL
TFIN
A control bit (TFIN) is provided which allows selection of the method of completion of the burst. If set
to 1, the burst completes at the next zero crossing. If left at 0, the burst completes a whole number
of sinusoids, avoiding potential problems with DC levels changing across AC coupling capacitors. At
the conclusion of a tone burst, the circuit ensures that at the end of the duration time of the last tone,
the tone continues to the next zero crossing point to ensure DC offsets are not created.
When a write to any MXSEL register is made with the BOTH bit set high, then the complementary
MXINL
TONE
MXINR
DAC
6
x TTIM[7:0])/ F
LEFT
DAC
RIGHT
DAC
TCLK
L Mix Switches (0-9)
R Mix Switches (0-9)
+
+
+
+
0/-6dB
0/-6dB
0/-6dB
0/-6dB
AI Rev 2.1 June 2001
Advanced Information
LINEOUTL
VAROUTL
VAROUTR
LINEOUTR
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