MSP 34x0G
DATA SHEET
Table 3–11: Write Registers on I2C Subaddress 12hex, continued
Register
Address
Function
Name
LOUDSPEAKER AND HEADPHONE PROCESSING
00 00hex
00 06hex
Volume Loudspeaker
Volume Headphone
VOL_MAIN
VOL_AUX
bit[15:8] volume table with 1 dB step size
7Fhex
7Ehex
...
+12 dB (maximum volume)
+11 dB
74hex
73hex
72hex
...
+1 dB
0 dB
−1 dB
02hex
01hex
00hex
FFhex
−113 dB
−114 dB
Mute (reset condition)
Fast Mute (needs about 75 ms until the signal is
completely ramped down)
bit[7:5]
higher resolution volume table
0
+0 dB
1
+0.125 dB increase in addition to the volume table
...
7
+0.875 dB increase in addition to the volume table
bit[4]
0
must be set to 0
bit[3:0]
clipping mode
0
1
2
3
reduce volume
reduce tone control
compromise
dynamic
With large scale input signals, positive volume settings may lead to signal clip-
ping.
The MSP 34x0G loudspeaker and headphone volume function is divided into a
digital and an analog section. With Fast Mute, volume is reduced to mute posi-
tion by digital volume only. Analog volume is not changed. This reduces any
audible DC plops. To turn volume on again, the volume step that has been used
before Fast Mute was activated must be transmitted.
If the clipping mode is set to “reduce volume”, the following rule is used: To
prevent severe clipping effects with bass, treble, or equalizer boosts, the inter-
nal volume is automatically limited to a level where, in combination with either
bass, treble, or equalizer setting, the amplification does not exceed 12 dB.
If the clipping mode is “reduce tone control”, the bass or treble value is
reduced if amplification exceeds 12 dB. If the equalizer is switched on, the gain
of those bands is reduced, where amplification together with volume exceeds
12 dB.
If the clipping mode is “compromise”, the bass or treble value and volume are
reduced half and half if amplification exceeds 12 dB. If the equalizer is switched
on, the gain of those bands is reduced half and half, where amplification
together with volume exceeds 12 dB.
If the clipping mode is “dynamic”, volume is reduced automatically if the signal
amplitudes would exceed −2 dBFS within the IC. For operation of Micronas
BASS, dynamic mode must be switched on.
32
May 27, 2003; 6251-476-1DS
Micronas
MICRONAS [ MICRONAS ]
