Installation Instructions

Hardware Installation
RVP8 User’s Manual
September 2005
2–28
Ack|CanCompress=1,Model=RVP8,Version=7.32
Your program can choose to evaluate or ignore any of these keywords. “CanCompress=1”
indicates that the DspExport computer supports compression. The host computer can then
choose to use compression if it wants to. When you first connect, you are in the “info only”
mode. That means that the server will only respond to INFO and OPEN commands. DspExport
supports only the 6 commands discussed individually below:
Read command (READ)
Example: “READ|100|” means read 100 bytes from the RVP8. Since the RVP8 interface is a
16-bit word interface, these read sizes should always be even. It will always reply with a “Ack|”
followed by 100 bytes of binary data, or with a “Nak|”, in other words there can be no partial
reads.
Write command (WRIT)
Example: “WRIT|<data>” Where <data> is some binary data. This data is written to the RVP8.
Again, the data size should be even.
Read Status command (STAT)
Example: “STAT|” This reads the status bits back from the RVP8. This is a 1 bit value, set to 1
if the RVP8 has data available in its output buffer. It will return either “Ack|0”, or “Ack|1”, or a
“Nak”. This is the equivalent of the dspr_status() call in the dsp library.
Set Information command (INFO)
Example: “INFO|ByteOrder=LittleEndian,WillCompress=1,Version=7.32”. This command can
be used to inform RVP8’s DspExport about the host computer. Current options available are:
ByteOrder to inform DspExport of the byte order of the host computer. This is needed because
all the data read or written to/from the RVP8 is in 16-bit words. If the host computer has a
different byte order from the RVP8, DspExport will byte swap the data.
WillCompress to inform DspExport to use compression or not. Compression is only used if
both sides agree to use it. The host computer should only set this to 1 if it received a
“CanCompress” of 1 on initial connection. The only thing compressed is the data from normal
READ commands. If it is compressed, it will reply with the acknowledge compressed string of
“AkC”. The compression program is the zlib compress and uncompress. The uncompress
function requires that the caller know the expected uncompressed size. This is true for RVP8
reads, because the reader always specifies the read size.
Version, send the IRIS version.
Read data available command (RDAV)
Example: “RDAV|100|2|” This means read up to 100 bytes of data from the RVP8 in individual
DMA transfers of 2 bytes each. Before each read, the status is checked to see if there is more
data available. If not, the read stops, and the number of bytes read is returned. This is merely a
performance enhancing command since the same feature is available by using the READ
command and the STAT command.