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参数资料
| 型号： | LM4546BVH/NOPB |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 消费家电 |
| 英文描述： | LM4550 AC '97 Rev 2.1 Multi-Channel Audio Codec with Stereo Headphone Amplifier, Sample Rate Conversion and National 3D Sound; Package: LQFP; No of Pins: 48; Qty per Container: 250/Tray |
| 中文描述： | SPECIALTY CONSUMER CIRCUIT, PQFP48 |
| 封装： | 7 X 7 MM, 1.40 MM HEIGHT, LQFP-48 |
| 文件页数： | 11/27页 |
| 文件大小： | 903K |
| 代理商： | LM4546BVH/NOPB |
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AC Link Serial Interface Protocol
(Continued)
SLOT 0, INPUT FRAME
Bit
Description
Comment
15
Codec Ready
Bit
1 = AC Link Interface Ready
14
Slot 1 data
valid
1 = Valid Status Address or
Slot Request
13
Slot 2 data
valid
1 = Valid Status Data
12
Slot 3 data
valid
1 = Valid PCM Data
(Left ADC)
11
Slot 4 data
valid
1 = Valid PCM Data
(Right ADC)
SDATA_IN: Slot 1 – Status Address / Slot Request Bits
This slot echoes (in bits 18 – 12) the 7-bit address of the
codec control/status register received from the controller as
part of a read-request in the previous frame. If no read-
request was received, the codec stuffs these bits with zeros.
Bits 11, 10 are Slot Request bits that support the Variable
Rate Audio (VRA) capabilities of the LM4546B. For all codec
Primary and Secondary modes, the left and right channels of
the DAC take PCM data from slots 3 and 4 in the Output
Frame respectively. The codec will therefore use bits 11 and
10 to request DAC data from these two slots. If bits 11 and
10 are set to 0, the controller should respond with valid PCM
data in slots 3 and 4 of the next Output Frame. If bits 11 and
10 are set to 1, the controller should not send data.
The codec has full control of the slot request bits. By default,
data is requested in every frame, corresponding to a sample
rate equal to the frame rate (SYNC frequency) – 48 kHz
when XTAL_IN = 24.576 MHz. To send samples at a rate
below the frame rate, a controller should set VRA = 1 (bit 0
in the Extended Audio Control/Status register, 2Ah) and
program the desired rate into the PCM DAC Rate register,
2Ch. Both DAC channels operate at the same sample rate.
Values for common sample rates are given in the Register
Description section (Sample Rate Control Registers, 2Ch,
32h) but any rate between 4 kHz and 48 kHz (to a resolution
of 1 Hz) is supported. Slot Requests from the LM4546B are
issued completely deterministically. For example if a sample
rate of 8000 Hz is programmed into 2Ch then the LM4546B
will always issue a slot request in every sixth frame. A
frequency of 9600 Hz will result in a request every fifth frame
while a frequency of 8800 Hz will cause slot requests to be
spaced alternately five and six frames apart. This determin-
ism makes it easy to plan task scheduling on a system
controller and simplifies application software development.
The LM4546B will ignore data in Output Frame slots that do
not follow an Input Frame with a Slot Request. For example,
if the LM4546B is expecting data at a 8000 Hz rate yet the
AC ’97 Digital Audio Controller continues to send data at
48000 Hz, then only those one-in-six audio samples that
follow a Slot Request will be used by the DAC. The rest will
be discarded.
Bits 9 – 2 are request bits for slots not used by the LM4546B
and are stuffed with zeros. Bits 1 and 0 are reserved and are
also stuffed with zeros.
SLOT 1, INPUT FRAME
Bits
Description
Comment
19
Reserved
Stuffed with "0" by LM4546B
18:12
Status Register
Index
Echo of the requested Status
Register address
11
Slot 3 Request
bit
(For left DAC
PCM data)
0 = Controller should send
valid data in Slot 3 of the
next Output Frame.
1 = Controller should not
send Slot 3 data.
10
Slot 4 Request
bit
(For right DAC
PCM data)
0 = Controller should send
valid data in Slot 4 of the
next Output Frame.
1 = Controller should not
send Slot 4 data.
9:2
Unused Slot
Request bits
Stuffed with "0"s by LM4546B
1,0
Reserved
Stuffed with "0"s by LM4546B
SDATA_IN: Slot 2 – Status Data
This slot returns 16-bit status data read from a codec control/
status register. The codec sends the data in the frame fol-
lowing a read-request by the controller (bit 15, slot 1 of the
Output Frame). If no read-request was made in the previous
frame the codec will stuff this slot with zeros.
SLOT 2, INPUT FRAME
Bits
Description
Comment
19:4
Status Data
Data read from a codec
control/status register.
Stuffed with “0”s if no
read-request in previous frame.
3:0
Reserved
Stuffed with "0"s by LM4546B
SDATA_IN: Slot 3 – PCM Record Left Channel
This slot contains sampled data from the left channel of the
stereo ADC. The signal to be digitized is selected using the
Record Select register (1Ah) and subsequently routed
through the Record Select Mux and the Record Gain ampli-
fier to the ADC.
This is a 20-bit slot and the digitized 18-bit PCM data is
transmitted in an MSB justified format. The remaining 2
LSBs are stuffed with zeros.
SLOT 3, INPUT FRAME
Bits
Description
Comment
19:2
PCM Record
Left Channel
data
18-bit PCM sample from left
ADC
1:0
Reserved
Stuffed with "0"s by LM4546B
LM4546B
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相关PDF资料 |
PDF描述 |
|---|---|
| LM4549BVH/NOPB | LM4549B AC '97 Rev 2.1 Multi-Channel Audio Codec with Sample Rate Conversion and National 3D Sound; Package: LQFP; No of Pins: 48; Qty per Container: 250/Tray |
| LM4549BVHX/NOPB | LM4549B AC '97 Rev 2.1 Multi-Channel Audio Codec with Sample Rate Conversion and National 3D Sound; Package: LQFP; No of Pins: 48; Qty per Container: 1000/Reel |
| LM4550BVH/NOPB | LM4550B AC '97 Rev 2.1 Multi-Channel Audio Codec with Stereo Headphone Amplifier, Sample Rate Conversion and National 3D Sound; Package: LQFP; No of Pins: 48; Qty per Container: 250/Tray |
| LM4550BVHX/NOPB | LM4550B AC '97 Rev 2.1 Multi-Channel Audio Codec with Stereo Headphone Amplifier, Sample Rate Conversion and National 3D Sound; Package: LQFP; No of Pins: 48; Qty per Container: 1000/Reel |
| LM4562NA/NOPB | LM4562 Dual High Performance, High Fidelity Audio Operational Amplifier; Package: MDIP; No of Pins: 8; Qty per Container: 40/Rail |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM4546BVHX | 功能描述:接口—CODEC RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel |
| LM4546BVHX/NOPB | 功能描述:接口—CODEC RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel |
| LM4546VH | 制造商:Texas Instruments 功能描述:SPECIALTY CONSUMER CIRCUIT, PQFP48 |
| LM4547VH | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Soundcard Circuits |
| LM4548 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:AC ’97 Rev 2 Codec with Sample Rate Conversion and National 3D Sound |
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