LM4546AVHX/NOPB National Semiconductor, LM4546AVHX/NOPB Datasheet - Page 16

• Manufacturer Part Number: LM4546AVHX/NOPB
• Manufacturer: National Semiconductor

Specifications of LM4546AVHX/NOPB

• Single Supply Voltage (typ): 3.3/5V
• Single Supply Voltage (min): 3/4.2V
• Single Supply Voltage (max): 5.5V
• Package Type: LQFP
• Lead Free Status / RoHS Status: Compliant

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Extended Audio Status/Control Register (2Ah)
This read/write register provides status and control of the
Variable Sample Rate function. Setting the LSB of this regis-
ter to "1" enables Variable Rate Audio (VRA) mode and allows
DAC and ADC sample rates to be programmed via registers
2Ch and 32h.
Sample Rate Control Registers (2Ch, 32h)
These read/write registers are used to set the sample rate for
the left and right channels of the DAC (2Ch) and the ADC
(32h). When Variable Rate Audio is enabled via bit-0 of Reg-
ister 2Ah, the sample rates can be programmed, in 1Hz
increments, to be any value from 4kHz to 48kHz. Below is a
PRO
VRA
PR1
PR2
PR3
PR4
BIT
BIT
PCM in ADC's and Input Mux powerdown
Analog Mixer powerdown (VREF still on)
0 = VRA off (48kHz fixed), 1 = VRA on
Digital Interface (AC Link) powerdown
Analog Mixer powerdown (VREF off)
Pin46 (ID1)
connected)
PCM out DAC's powerdown
NC (not
DVdd
DVdd
GND
GND
(external clk off)
Function
Function
100985 Version 4 Revision 1
Pin45 (ID0)
connected)
NC (not
DVdd
DVdd
GND
GND
Reg 28h ID1
Print Date/Time: 2009/04/29 09:52:43
16
0
0
0
1
1
Extended Audio ID Register (28h)
This read only register identifies which AC97 Extended Audio
features are supported. The LM4546 provides for VRA (Vari-
able Rate Audio) and Multiple Codec support. VRA is indicat-
ed by a "1" in the LSB of register 28h. The two MSB's, ID1
and ID0, show the current codec configuration as connected
via external pins 45 and 46.
list of the most common sample rates and their corresponding
register values.
Reserved Registers
Do not write to these registers as they are reserved.
PR5
PR6
BIT
Reg 28h ID0
SR15:SR0
0
0
1
0
1
AC44h
2B11h
3E80h
BB80h
1F40h
5622h
Codec Mode
Primary
Primary
Secondary 1
Secondary 2
Secondary 3
Internal Clk disable
Function
not used
Sample Rate (Hz)
11025
16000
22050
44100
48000
8000