ACS422A68TAGZBX8 IDT, ACS422A68TAGZBX8 Datasheet - Page 15

• Manufacturer Part Number: ACS422A68TAGZBX8
• Description: Interface - CODECs
• Manufacturer: IDT

Specifications of ACS422A68TAGZBX8

• Rohs: yes
• Part # Aliases: IDTACS422A68TAGZBX8

ACS422x68
LOW-POWER, HIGH-FIDELITY, INTEGRATED CODEC
©2011 INTEGRATED DEVICE TECHNOLOGY, INC.
3.3.
The signal volume can be controlled digitally, across a gain and attenuation range of -95.25dB to 0dB (0.375dB steps).
The level of attenuation is specified by an eight-bit code, ‘DACVOL_x’, where ‘x’ is L, or R. The value “00000000” indi-
cates mute; other values select the number of 0.375dB steps above -95.625dB for the volume level.
3.4.
The ACS422x68 has a dual 6-band digital parametric equalizer to enable fine tuning of the audio response and prefer-
ences for a given system. Each EQ may be enabled or disabled independently. Typically one EQ will be used for
speaker compensation and disabled when only headphones are in use while the other EQ is used to alter the audio to
make it more pleasing to the listener. This function operates on the digital audio data before it is converted back to ana-
log by the audio DACs.
In all, 186 bytes of memory are required to store the parameters for each equalizer: each filter requires 5, 24-bit coeffi-
cients. There are 6 filters per channel, requiring a total of 180 bytes of EQ coefficient RAM. Two additional 24-bit values
per channel store the prescale value, resulting in 372 bytes total, described later. Rather than having all 372 bytes be in
the I2C address space of the device, access to the EQ ram occurs through the Control/Status registers.
R33 (21h)
Gain Control
(GAINCTL)
R4 (04h)
Left DAC
Volume Control
R5 (05h)
Right DAC
Volume Control
Register Address
Register Address
Digital DAC Volume Control
Parametric Equalizer
Bit
5:4
Bit
7:0
7:0
7
6
3
2
1
0
7
zerodet_flag
zerodet_flag
DACVOL_R
DACVOL_L
zerodetlen
auto_mute
RSVD
RSVD
RSVD
RSVD
Label
Label
[7:0]
[7:0]
Table 8. DAC Volume Control Registers
Table 7. Gain Control Register
Type
Type
RW
RW
RW
RW
R
R
R
R
R
R
Default
Default
15
(0dB)
(0dB)
FF
FF
0
0
2
0
1
0
0
0
1 = zero detect length exceeded.
Reserved for future use.
Enable mute if input consecutive zeros exceeds this
length. 0 = 512, 1 = 1k, 2 = 2k, 3 = 4k samples
Reserved for future use.
1 = auto mute if detect long string of zeros on input
Reserved for future use.
Reserved for future use.
1 = zero detect length exceeded.
Left DAC Volume Level
0000 0000 = Digital Mute
0000 0001 = -95.25dB
0000 0010 = -94.875dB
... 0.375dB steps up to
1111 1111 = 0dB
Note: If DACVOLU is set, this setting will take effect
after the next write to the Right Input Volume register.
Right DAC Digital Volume Level
0000 0000 = Digital Mute
0000 0001 = -95.25dB
0000 0010 = -94.875dB
... 0.375dB steps up to
1111 1111 = 0dB
Description
Description
ACS422X68
V1.6 01/13