Hi Troy,
Per the OpenCPI_Generic_Authoring_Model.pdf document, arraylength
specifies an array, which is of fixed size.
SequenceLength specifies a variable length sequence, which has a bounded
size.
In general, when a sequence is part of a message, the message data must
contain an "element count" as an aligned 32 bit value, before the
elements of the sequence (consistent with CDR marshalling in CORBA and
DDS etc.).
But there is an important, simplifying special case: when the whole
message/operation is a single sequence argument, this element count is
implied by the byte length of the overall message (unless the sequence
elements themselves are variable length). Thus typical simple variable
length messages of fixed size types are described as a sequence, but
only contain the data elements of the sequence, and do not contain an
element count. This keeps common and simple cases simple.
The byte length of the overall message is specified in the external port
API and the RCC/OCL worker's port interface.
For HDL worker ports using the WSI/stream profile, it is conveyed by the
OCP burst length (number of "words") times the data path width (in
bytes), with the last word in the burst subject to byte-enables.
If any of this isn't clear, please say so, since we will be updating the
doc shortly!
Jim
On 3/7/12 4:44 PM, Ziersch, Troy (Contractor) wrote:
*UNCLASSIFIED*
Hi,
In test_protocol.xml given below is the ArrayLength of Samples an
absolute size or a maximum size?
I'd like to have a protocol where the amount of samples is variable up
to a given maximum.
Thanks,
Troy
<Protocol>
<Operation Name="Samples">
<Argument Name="data" Type="Short" ArrayLength="4k"/>
</Operation>
<Operation Name="Sync"/>
<Operation Name="Time">
<Argument Name="time" Type="ULongLong"/>
</Operation>
</Protocol>
*IMPORTANT*: This email remains the property of the Department of
Defence and is subject to the jurisdiction of section 70 of the Crimes
Act 1914. If you have received this email in error, you are requested
to contact the sender and delete the email.
_______________________________________________
opencpi_dev mailing list
[email protected]
http://lists.opencpi.org/listinfo.cgi/opencpi_dev-opencpi.org
_______________________________________________
opencpi_dev mailing list
[email protected]
http://lists.opencpi.org/listinfo.cgi/opencpi_dev-opencpi.org
