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TSC2300
SLAS372 — NOVEMBER 2002
Bit 15 DAMUL
Left DAC Mute. This bit is used to mute the input to the Left Channel DAC. The user can set this bit to mute the DAC
while retaining the previous gain setting in DAVL[6:0], so that the gain control returns to the previous gain setting when
DAMUL is cleared. When the DAMUL bit is set, the left DAC digital gain control soft-steps down to its lowest level, then
all zeroes are sent to the interpolation filter of this DAC. This procedure is used to reduce any audible artifacts (pops or
clicks) of the mute procedure. This soft-stepping process is reversed when the DAMUL bit is cleared (unmute).
Table 34. Left DAC Mute
DAMUL
DESCRIPTION
0
Left channel DAC is active.
1
Left channel DAC is mute. (default)
Bits [14:8] DAVL6- DAVL0
Left DAC Volume Control. These 7 bits control the gain setting of the left channel DAC volume control PGA. This
volume control can be programmed from -63.5 dB to 0dB in 0.5-dB steps. Full volume (0dB) corresponds to a setting
of 7Fh. Full attenuation (-63.5 dB) corresponds to 00h. The default volume setting is 0 dB.
DAVL[6:0] = 1111111 (127d) = 0 dB (default)
DAVL[6:0] = 0000000 (000d) = -63.5 dB (Min)
1LSB = 0.5 dB
Bit 7 DAMUR
Right DAC Mute. This bit is used to mute the input to the right channel DAC. The user can set this bit to mute the DAC
while retaining the previous gain setting in DAVR[6:0], so that the gain control returns to the previous gain setting when
DAMUR is cleared. When the DAMUR bit is set, the left DAC digital gain control soft-steps down to its lowest level,
then all zeroes are sent to the interpolation filter of this DAC. This procedure is used to reduce any audible artifacts
(pops or clicks) of the mute procedure. This soft-stepping process is reversed when the DAMUR bit is cleared
(unmute).
Table 35. Right DAC Mute
DAMUR
DESCRIPTION
0
Right channel DAC is active.
1
Right channel DAC is mute. (default)
Bits [6:0] DAVR6- DAVR0
Right DAC Volume Control. These 7 bits control the gain setting of the right channel DAC volume control. This volume
control can be programmed from -63.5 dB to 0 dB in 0.5-dB steps. Full volume (0dB) corresponds to a setting of 7Fh.
Full attenuation (-63.5 dB) corresponds to 00h. The default volume setting is 0 dB.
DAVR[6:0] = 1111111 (127d) = 0 dB (default)
DAVR[6:0] = 0000000 (000d) = -63.5 dB (Min)
1LSB = 0.5 dB
ANALOG AUDIO BYPASS PATH VOLUME CONTROL REGISTER (Page 02, Address 03h)
The bypass path volume control register controls the independent programmable gain amplifiers (PGA’s) on the left
and right channel analog audio bypass paths of the TSC2300. These bypass paths direct the line inputs directly to the
line and headphone outputs entirely in the analog domain, with no A/D or D/A conversion. This feature can be used for
playback of an external analog source, such as an FM stereo tuner through the TSC2300’s headphone amplifier. The
gain of these PGA’s can be adjusted from -35.5 dB to +12 dB in 0.5 dB steps. The bypass paths can also be muted,
so that no signal is transmitted.
The bypass path volume control register is formatted as follows:
69