uda1335h NXP Semiconductors, uda1335h Datasheet - Page 17

• Manufacturer Part Number: uda1335h
• Description: Universal Serial Bus Usb Audio Playback Recording Peripheral Aprp
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Mute control
Mute is one of the sound features as defined in the “USB
Device Class Definition for Audio Devices” . The mute
control request data bMute controls the position of the
mute switch. The position can be either on or off. When
bMute is true the feature unit is muted. When bMute is
false the feature unit is not muted.
When the mute is active for the master channel, the value
of the sample is decreased smoothly to zero following a
raised cosine curve. There are 32 coefficients used to step
down the value of the data, each one being used 32 times
before stepping to the next. This amounts to a mute
transition of 23 ms at f
released, the samples are returned to the full level again
following a raised cosine curve with the same coefficients
being used in reversed order.
Table 8 Treble control characteristics
1998 Aug 28
Universal Serial Bus (USB) Audio
Playback Recording Peripheral (APRP)
B7
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
B6
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
B5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
s
= 44.1 kHz. When the mute is
B4
bTREBLE
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
1
B3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
0
1
0
1
B2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
1
1
B1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
0
0
0
1
17
The mute, on the master channel is synchronized to the
sample clock, so that operation always takes place on
complete samples.
A mute can be given via the host or by pressing a
predefined GP pin.
Treble control
The treble control is available for the master channel of the
UDA1335H. The treble range is from 0 to 6 dB in steps of
2 dB. It should be noted that the negative treble values as
defined in the “USB Device Class Definition for Audio
Devices” are not supported by the UDA1335H; values
below 0 dB are returned as 0 dB. The corner frequency is
1500 Hz. Table 8 gives the mapping of the bTreble value
upon the actual treble setting of the USB APRP.
B0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
1
1
1
TREBLE USB HOST
31.75
(dB)
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
2.75
3.00
3.25
5.25
7.25
9.25
...
...
...
...
Preliminary specification
TREBLE USB APRP
UDA1335H
(dB)
0
2
4
6
6
6
6