LM4550BVH/NOPB National Semiconductor, LM4550BVH/NOPB Datasheet - Page 28

• Manufacturer Part Number: LM4550BVH/NOPB
• Description: IC AC '97 AUDIO CODEC 48-LQFP
• Manufacturer: National Semiconductor
• Type: Audio Codec '97r

Specifications of LM4550BVH/NOPB

• Data Interface: Serial
• Resolution (bits): 18 b
• Number Of Adcs / Dacs: 2 / 2
• Sigma Delta: Yes
• Dynamic Range, Adcs / Dacs (db) Typ: 90 / 89
• Voltage - Supply, Analog: 4.2 V ~ 5.5 V
• Voltage - Supply, Digital: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Audio Codec Type: Stereo
• No. Of Adcs: 2
• No. Of Dacs: 2
• No. Of Input Channels: 8
• No. Of Output Channels: 3
• Adc / Dac Resolution: 18bit
• Sampling Rate: 48kSPS
• Interface Type: Serial
• Supply Voltage Range: 3V To 5.5V, 4.2V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM4550BVH; *LM4550BVH/NOPB; LM4550BVH

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Multiple Codecs
The Codec Identity is determined by the inverting input pins
ID1#, ID0# (pins 46 and 45) and can be read as the value of
the ID1, ID0 bits (D15, D14) in the Extended Audio ID
register, 28h of the target codec.
In addition to the Codec Identity bits (ID1, ID0), the read-only
Extended Audio ID register (28h) contains the AMAP bit
(D9). The AMAP bit indicates support for the (optional) AC
’97 Rev. 2.1 compliant mappings from slots in AC Link Out-
SLOT 0: TAG bits in Output Frames (controller to codec)
Extended Audio ID register (28h): Support for Multiple Codecs
Note 11: AC ’97 Rev 2.1 specifies this allocation of 5.1 Audio channels to these slots in the AC Link Output Frame
Frame
Primary
Secondary 1
Secondary 2
Secondary 3
Bit 15
Reg
28h
Codec Identity
Valid
Mode
Extended
Audio ID
Slot 1
Valid
Name
14
Slot 2
Valid
13
D15 D14 D13 D12 D11 D10
ID1
(D15, 28h)
Slot 3
ID1
Valid
0
0
1
1
ID0
12
(Continued)
Slot 4
X
Valid
11
(D14, 28h)
X
TABLE 1. AMAP Slot-to-DAC Audio MAPping
ID0
0
1
0
1
10
X
X
Slot 6
Valid
9
X
From Slot #
AMAP
Slot 7
Valid
D9
3
3
7
6
8
Left DAC data
28
D8
Slot 8
Valid
X
Left
Left
Left Surround
Center
7
put Frames to the audio DACs for each of the four Codec
Identity modes. AMAP = 1 indicates that the default mapping
(as realized after reset) of Slots-to-DACs conforms to Table
1. Slots in AC Link Input Frames are always mapped such
that PCM data from the left ADC channel is carried by slot 3
and PCM data from the right ADC channel by slot 4. Output
Frames are those carried by the SDATA_OUT signal from
the controller to the codec while Input Frames are those
carried by the SDATA_IN signal from the codec to the
controller.
5.1 Audio channel
D7
X
Slot 9
(Note 11)
Valid
6
D6
X
D5
5
X
X
D4
X
From Slot #
4
X
D3
X
4
4
8
9
3
X
Right DAC data
D2
X
Right
Right
Right Surround
LFE
5.1 Audio channel
2
X
D1
X
(Note 11)
VRA X201h
D0
ID1
1
Default
ID0
0