User guide

108 DC 900-1338I
Protocol Software Toolkit Programmer Guide
the protocol task removes the buffer from the link-to-board queue, calls the appropri-
ate postprocessor to process the data before passing it to the application program, posts
it to the board-to-server queue, and resumes the utility task which passes the message
to the host.
Whenever the protocol task removes a buffer from the head of the link-to-board queue,
it restocks the queue. In this way, the protocol task maintains several available buffers
for received messages.
Figure 6–9 shows a link-to-board queue containing four buffers. Two are filled and
waiting for removal by the protocol task. The third buffer is set up for the current
receive.
Figure 6–9: Sample Link-to-Board Queue
System Buffer
Header
data
System Buffer
Header
data
System Buffer
Header
System Buffer
Header
ICP Header ICP Header ICP Header ICP Header
queue
head
lct_frbuf
queue
tail
DMA transfer address
2401
Protocol HeaderProtocol Header
Protocol Header
Protocol Header