ADSP-214xx SHARC Processor Hardware Reference
14-17
Precision Clock Generator
The combined PCGs can provide a selection of synchronous clock fre-
quencies to support alternate sample rates for the ASRCs and external
DACs. However, the range of choices is limited by
CLKIN
and the ratio of
PCG_CLKx_O
:
SCLK
:
FS
which is normally fixed at 256:64:1 to support digital
audio left-justified, I
2
S and right-justified interface modes.
Many DACs also support 384, 512, and 786x FS for
PCG_CLKx_O
, which
allows some additional flexibility in choosing
CLKIN
.
Note the falling edge of
SCLK
must always be synchronous with both edges
of FS. This requires that the phase of the
SCLK
and FS signals for a com-
mon PCG (PCG A) be adjustable.
While the frequency of the master DAC clock (
PCG_CLKx_O
) must be syn-
chronous with the sample rate supplied to the external DAC, there is no
fixed phase requirement.
Figure 14-6. PCG Setup for I2S or Left-Justified DAI
ADSP-214xx
SPDIF
RX
ASRC
RxSCLK
RxLRCLK
SDATAIN
PCG_
CLKA_O
PLL
CCLK÷2
CCLK÷4
CCLK
PCLK
SDATAOUT
DAI_P8
DAI_P9
DAI_P10
STEREO DAC
LEFTOUT
RIGHTOUT
MCLKIN
DAI_P11
PCLK/4
FSYNCA (FSOUT)
SCLKA (64 FSOUT)
SCLKB (256 FSOUT)
FCLKIN
SPDIFIN
(FSIN, 44.1 kHz)
DAI_P19
SDATAIN
LRCLKIN
SCLKIN
FSOUT = 65.1 kHz
24-BIT
LEFT-JUSTIFIED
CD
PLAYER
HEAD PHONES
PCG_
CLKB_O
PCG_
FSA_O
www.BDTIC.com/ADI
Содержание SHARC ADSP-214 Series
Страница 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...