DS543 Datasheet, PDF (10/24 Pages) Xilinx, Inc – MOST Network Interface Controller v1.4

MOST Network Interface Controller v1.4
MOST Controller Design Parameters
The MOST NIC is configurable through a set of design parameters accessible through the CORE Generator
Graphical User Interface (GUI).
Operating Modes
The core supports two configuration modes: Full master/slave, and slave with pseudo-master modes
only (ring break diagnostic and loopback modes).
Word Count Triggers
The MOST NIC core supports 16 logical channel buffers for the receive and transmit directions, for a
total of 32 logical channel buffers. In each direction, eight logical channels are dedicated for OPB, four
for streaming ingress, and four for streaming egress. All buffers can assert interrupts to an external
microprocessor to indicate that the buffer requires processing. The word count at which the interrupt is
asserted is configurable, as defined in Table 1.
In addition, all streaming ports also assert a trigger to assist in processing for any logic directly con-
nected to the port. Word counts can be chosen separately for ingress buffers and egress buffers. All
ingress buffers use the same word counts, and all egress buffers use the same word counts. The avail-
able interrupts for each group of logical channel are also illustrated in Figure 5.
Table 1: Word Count Parameters
Name
Possible
Values
Default
Description
C_FWC
8, 16
16
Full Word Count. The received word count at which an interrupt is
generated.
C_EWC
16, 8
16
Empty Word Count. The available transmit word count at which an
interrupt is generated.
Figure Top x-ref 5
Recieve Channels
Transmit Channels
Logical
Channels
0-7
General Purpose
MOST Ring
OPB
(Full Determination)
General Purpose
OPB
(Empty Determination)
MOST Ring
Logical
Channels
8-11
Logical
Channels
12-15
Ingress
Egress
Streaming
(Empty Determination)
OPB
(Full Determination)
MOST Ring
Ingress
Streaming
(Full Determination)
Egress
Figure 5: Logical Channel Support
Streaming
(Empty Determination)
MOST Ring
OPB
(Empty Determination)
Streaming
(Full Determination)
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DS543 September 19, 2008