Draft 1/16/97
L64007 MPEG-2, DVB, JSAT Transport Demultiplexer Technical Manual
3-5
PRE.4 for Rev. D
Copyright 1997 by LSI Logic Corporation. All rights reserved.
D[15:0] with valid data. Data must be stable on the data
bus during the set-up time before the LOW-to-HIGH tran-
sition of the UDS and LDS signals.
3.2
System and
Audio Clocks
ACLK
Audio Clock
Output
This clock signal outputs to the L64002 A/V decoder as
well as an external over-sampling DAC in programmable
rates, based on 256 times or 384 times the original audio
sample rate. The clock frequency is determined by the
conguration of the DCO-DIV and REF_DIV registers
details).
MCLK
Master Clock Input
Input
This master clock input drives all the L64007 internal
blocks. The clock recovery block of the L64007 takes this
signal to drive the local master clock counter. Samples of
the local master clock are taken by the host processor
and compared to the extracted PCR values. This is per-
formed as part of the frequency lock algorithm. MCLK
drives the A/V decoder device.
3.3
Audio/Video
Decoder
Interface
AREQ
Audio Data Request
Input
This active LOW input signal indicates that the external
audio decoder is requesting audio PES data.
AVALID
Audio Data Valid
Output
This active HIGH signal indicates that valid audio data is
being output to the L64002. In serial mode, when AVALID
is asserted, audio data coming on AVSD is latched in the
L64002/L64005 on the rising edge of AVCLK. In parallel
mode, the rising edge of AVALID latches audio data on
the AUX[7:0] in the L64002.
AVCLK
Audio Video Clock Output (27 MHz)
Output
The rising edge of this active HIGH output clock signal to
the L64002/L64005 A/V decoder latches a single bit of
coded MPEG data coming out on the AVSD (in a serial
operation mode) into the A/V decoder when VVALID or
AVALID are asserted and AUXV is valid.