TCD6000 Datasheet, PDF (22/36 Pages) Tripath Technology Inc. – 6 CHANNEL CLASS-T DIGITAL AUDIO PROCESSOR USING DIGITAL POWER PROCESSINGTM TECHNOLOGY

Tripath Technology, Inc. – Preliminary Technical Information
The Soft-Mute function will turn off volume selectively on any of the 6 channels. Setting control bits M1
through M6 to ‘1’ will issue a Soft-Mute on the corresponding channels. If the VRE bit in the Volume Change
Control Register is set, the volume will first ramp down at a rate defined by the Volume Ramp Rate Register.
Soft-Mute has no affect on whether the differential outputs (Y1 and Y1B through Y6 and Y6B) continue to
switch or not. Clearing bits M1 through M6 to ‘0’ will re-establish volume on all channels at a rate defined by
the Volume Ramp Enable settings.
The Hard-Mute function is enabled by setting control bit HM high. This function starts with a Soft-Mute on all
channels simultaneously. If the VRE bit in the Volume Change Control Register is set, the volume will first
ramp down at a rate defined by the Volume Ramp Rate Register. Once volume is turned off on all channels,
all differential outputs (Y1 and Y1B through Y6 and Y6B) stop switching. This will reduce power consumption
in the power stages driven by the TCD6000.
When control bit HM is cleared to ‘0’, the Hard-Mute condition is removed, and the TCD6000 goes through
an automatic DC calibration cycle. Once the calibration cycle is complete, volume is re-established on all
channels at a rate defined by the Volume Ramp Enable settings.
The Auto-Mute function is enabled by setting the AM bit to ‘1’. This function detects digital silence (all data
input bits at 0) on all 6 channels lasting more than a pre-defined delay. It then issues a Hard-Mute. The
delay is determined by the contents of the Auto-Mute Timing Register (described below). Upon arrival of
non-zero data on any channel, the Hard-Mute condition is automatically removed. The volume on all 6
channels is re-established at a rate defined by the Volume Ramp Enable settings. The Auto-Mute function
reduces power consumption in the power stages during periods of silence.
Auto-Mute Timing
Addr
2Dh
Register Name
Auto-Mute Timing
Default
D7
AM7
0
D6
AM6
0
D5
AM5
0
D4
AM4
0
D3
AM3
0
D2
AM2
0
D1
AM1
0
D0
AM0
0
This register is only used if the Auto-Mute function is enabled. Its contents specify the duration of silence on
all 6 channels before a Hard-Mute condition is issued. If the number entered is “N”, the duration of silence is
equal to:
(2N + 1) x (1,048,576 periods of LRCK)
As an example, if N = 1 and the period of LRCK is 22.67usec, the period of silence required before a Hard-
Mute condition is issued is:
3 x 1,048,576 x 22.67usec = 71.3 seconds
22
TCD6000 – Rev. 1.0/09.04