IPSERIALLITE Altera, IPSERIALLITE Datasheet - Page 101

• Manufacturer Part Number: IPSERIALLITE
• Manufacturer: Altera

Specifications of IPSERIALLITE

• Lead Free Status / RoHS Status: Not Compliant

Specifications
Altera Corporation
August 2005
Minimizing Logic Utilization
The amount of logic required for a SerialLite link depends heavily on the
features chosen. The Parameterize - SerialLite MegaCore function wizard
displays an estimate of LE usage to help you select features with visibility
into the impact on LE utilization. This display is only an estimate and
does not necessarily change with every feature setting change; if you
want a more accurate measure of the logic required for your
configuration, you must synthesize the design.
The following features have a significant impact on logic usage:
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Lane count: running fewer lanes at higher bit rates, if possible, uses
less logic (but places more of a burden on meeting performance).
CRC: significant savings can be made by eliminating CRC, or in
particular, moving from CRC-32 to CRC-16 in high-lane-count
designs. If you are using CRC-32, evaluate carefully whether the
extra protection over CRC-16 is really worthwhile, because CRC-16
uses far fewer resources.
Port selection: having two ports instantiated uses significantly more
logic than having one port. If you don’t need the nesting or
retry-on-error features of the priority data port, consider using
channel multiplexing on the regular data port to manage multiple
streams without using the priority data port. Alternatively, if you
require the retry-on-error feature and can forego packet nesting, you
can eliminate the regular data port and use only the priority data
port, with channel multiplexing allowing you to differentiate your
data streams.
Polarity reversal: if you have confidence that the SerialLite link
connection medium has the correct differential pair polarity, opting
to test polarity but not reverse it saves logic.
Packet mode: packet mode requires more logic than streaming mode
for data encapsulation. In general, streaming mode on the regular
data port gives you the fastest, smallest implementation.
Retry on error: this feature requires logic to generate
acknowledgments and keep track of the packet flow.
Flow Control: this feature requires logic to monitor the FIFO buffer
levels and to generate and act upon PAUSE instructions.
MegaCore Function Version 1.1.0
SerialLite MegaCore Function User Guide
3–69