參數(shù)資料
型號: LM4549
廠商: National Semiconductor Corporation
元件分類: Codec
英文描述: AC ’97 Rev 2.1 Codec with Sample Rate Conversion and National 3D Sound
中文描述: 交流\u0026#39;97活2.1編解碼器的采樣率轉(zhuǎn)換和國家3D聲音
文件頁數(shù): 12/18頁
文件大?。?/td> 324K
代理商: LM4549
Application Information
AC Link Serial Interface Protocol
AC Link Output Frame: SDATA_OUT (output from
controller, input to LM4549)
The audio output frame (output from AC ’97 Controller) con-
tains control and PCM data targeted for the LM4549 control
registers and stereo DAC. The Tag slot, slot 0, contains 16
bits that tell theAC Link interface circuitry on the LM4549 the
validity of the following data slots.
A new audio output frame is signaled with a low to high tran-
sition of SYNC. SYNC is synchronous to the rising edge of
BIT_CLK. On the next rising edge of BIT_CLK, the AC ’97
Controller drives SDATA_OUT with the first bit of slot 0. The
LM4549 samples SDATA_OUT on the falling edge of BIT-
_CLK. The AC ’97 Controller will continue outputting the
SDATA_OUT stream on each successive rising edge of BIT-
_CLK.
SDATA_OUT Slot 0: Tag Phase
The first bit of slot 0 is designated the
Valid Frame
bit. If
this bit is 1, it indicates that the current data frame contains
at least one slot of valid data and the LM4549 will further
sample the next four bits to determine which frames do in
fact have valid data. Valid slots are signified by a 1 in their re-
spective slot bit position.
Bit
Description
Comment
15
Valid Frame
1 = This frame has valid
data.
14
Control
register
address
Control
register data
Left Playback
PCM Data
1 = Control Address is
valid.
13
1 = Control Data is valid.
12
1 = Left PCM Data is
valid.
DS101035-4
FIGURE 3. AC 97 Bidirectional Audio Frame
DS101035-6
FIGURE 4. AC Link Audio Output Frame
DS101035-5
FIGURE 5. Start of Audio Output Frame
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相關代理商/技術參數(shù)
參數(shù)描述
LM4549A 制造商:NSC 制造商全稱:National Semiconductor 功能描述:AC ’97 Rev 2.1 Codec with Sample Rate Conversion and National 3D Sound
LM4549AVH 制造商:Rochester Electronics LLC 功能描述:AC97 REV2.1 CODEC - Bulk 制造商:OC White Company 功能描述:Audio Codec 2ADC / 2DAC 18-Bit 48-Pin LQFP Tray
LM4549AVH WAF 制造商:Texas Instruments 功能描述:
LM4549AVH/NOPB 制造商:Texas Instruments 功能描述:Audio Codec 2ADC / 2DAC 18-Bit 48-Pin LQFP Tray
LM4549AVHX 制造商:Rochester Electronics LLC 功能描述:AC97 REV2.1 CODEC - Bulk