14
L64222 DVD Audio/Video Decoder
interface is 20 Mbytes/s in worst case conditions. The
peak data rate may increase above this depending on
system SDRAM usage.
PREQ_INn
PCM Input FIFO Request
Output
The L64222 asserts this signal when it is ready to receive
a new byte of data in the PCM Input FIFO, i.e., when the
FIFO is not near full (less than 25 bytes unread). The
PCM Input FIFO allows the host to send Linear PCM
audio samples to the Audio Decoder in the L64222.
PREQ_INn can be used as a request signal to an
external DMA controller.
PREQ_OUTn PCM Output FIFO Request
Output
The L64222 asserts this signal when there is data in the
PCM Output FIFO. The PCM Output FIFO allows the
host to receive Linear PCM audio samples from the
output of the Audio Decoder in the L64222. PREQ_OUTn
can be used as a request signal to an external DMA
controller.
Channel Interface
AREQn
Audio Transfer Request
Output
The L64222 asserts AREQn when it is ready to receive
a new byte of coded audio data in A/V PES stream mode
(from a transport stream demultiplexer) or a new byte of
any data in program stream modes. The decoder is ready
when the channel input FIFO is not near full.
VREQn
Video Transfer Request
Output
The L64222 asserts VREQn when it is ready to receive
a new byte of coded audio data in A/V PES stream mode
(from a transport stream demultiplexer). The decoder is
ready when the channel input FIFO is not near full.
VREQn is not used in program stream modes.
CH_DATA [7:0]
Channel Data Bus
Input
The CH_DATA bus is used to transfer 8-bit, parallel
bitstreams into the L64222. The maximum transfer rate
over this interface is 20 Mbytes/s in worst case
conditions. The peak data rate may increase above this
rate depending on system SDRAM usage.