StreamSwitch Entity Reference

This module implements a PCIe packet switch transfering packets between streams. More...

Inheritance diagram for StreamSwitch:

Libraries
ieee
unisim
work

Use Clauses
std_logic_1164
numeric_std
vcomponents
NvmeStoragePkg	Package <NvmeStoragePkg>
NvmeStorageIntPkg	Package <NvmeStorageIntPkg>

Generics
NumStreams	integer := 8
	The number of streams.

Ports
clk	in	std_logic
		The interface clock line.
reset	in	std_logic
		The active high reset line.
streamIn	inout	AxisStreamArrayType ( 0 to NumStreams - 1 ) := ( others = > AxisStreamInput )
		Input streams.
streamOut	inout	AxisStreamArrayType ( 0 to NumStreams - 1 ) := ( others = > AxisStreamOutput )
		Output streams.

Detailed Description

This module implements a PCIe packet switch transfering packets between streams.

Author

Terry Barnaby (terry.nosp@m..bar.nosp@m.naby@.nosp@m.beam.nosp@m..ltd..nosp@m.uk)

Date

2020-04-08

Version

1.0.0

This switch sends PCIe packets between streams. There are two AXI streams per logical stream one is for input packets and one for output packets. Streams are numbered 0 to NumStreams-1. It expects Xilinx PCIe Gen3 PCIe packet headers to be used. Packets are switched based on the address fields bits 27 downto 24 in the case of request packets and on the requesterId field in the case of replies. A special bit, 29, is set in the reply header to indicate that the packet is a reply type. The switch uses a priority based on the input stream number, with 0 being the highest priority. When the switch sees a valid signal on one of the streams and its desitation stream is ready then the switch will send a complete packet, using the "last" signal to denote the end of packet. Note this simple implementation can only send one packet at a time. This simple switch only allows one packet to be transfered at a time and uses unregistered outputs to reduce latency.

Copyright

2020 Beam Ltd, Apache License, Version 2.0 Copyright 2020 Beam Ltd Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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The documentation for this class was generated from the following file:

• /src/dune/source/DuneNvme/src/StreamSwitch.vhd