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+# OpenExSys_NoC
+OpenExSys_NoC a mesh-based network on chip IP.
+
+## Getting Started
+
+### Simulation
+
+Currently, OpenExSys_NoC uses vcs to do simulation.
+
+```sh
+# set environment varibales
+source env/sourceme
+# go to the tb folder
+cd tb
+# Compile the sources, with a mesh configuration
+make mesh
+# Run the simulation
+make run
+```
+
+### Architecture
+
+Please refer to [Architecture](./doc/noc_spec.md)
+
+### Router Interface Signals
+
+Please refer to [Interface](./doc/noc_intf.md).
+
+### Tester
+
+The NoC tester is a unit test environment for this IP. It consists of following components:
+
+![alt noc_tester](./doc/image/noc_tester.png)
+
+**Test Generator**, which generates test packages according to the specified test policy and sends 
+them to the sender. We have implemented several commonly used synthetic traffic patterns for users 
+to choose from.
+
+| Name           | Pattern                                                                                                                                        |
+| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- |
+| Uniform Random | Generates a random destination ID from the available destinations.                                                                             |
+| Diagonal       | Packets move diagonally across the network from one corner to the opposite corner.                                                             |
+| Bit Complement | Computes the destination node as the complement of the source node's position in the mesh network.                                             |
+| Bit Reverse    | Computes the destination node as the bit-reversed index of the source node in the mesh network.                                                |
+| Bit Rotation   | Computes the destination node by rotating the source node's ID by one bit                                                                      |
+| Neighbor       | Packets are sent from a node to its neighbor node in a fixed order.                                                                            |
+| Shuffle        | The network is divided into several smaller subnetworks, and packets are shuffled within each subnetwork before being sent to the destination. |
+| Transpose      | Packets move between nodes on the same row and column, forming a transpose-like pattern.                                                       |
+| Tornado        | Packets move in a pattern that resembles a tornado, starting from one corner of the network and moving towards the opposite corner.            |
+
+**Sender**, which then injects packages generated by test generator into the design under test (DUT) 
+for processing.
+
+**Routing Monitor**, which checkes the routing path when each middle router receives 
+the package. In case of a mismatch between the expected and the actual
+routing path, the routing monitor invokes the wrong routing path error. This component
+helps in ensuring that the routing path of the test packages is correct, and the packets are
+flowing through the correct path.
+
+**Receiver**, which extracts the packages out of the DUT and refers to the
+scoreboard for target node ID checking. The scoreboard, as the name suggests, is
+responsible for keeping a score of the packets and their state at various stages of the
+verification process. It performs several functions such as adding a new entry when a
+sender injects a package into the DUT, removing an old entry when the receiver extracts
+a package out of the DUT, and checking the entry when the receiver receives a package
+from the DUT.
+
+**Scoreboard**, which indexes the entry by source node ID and transaction ID and checks
+the target node ID against the receiver's node ID. If there is a mismatch, it invokes the
+wrong target error. Additionally, the scoreboard invokes an inflight package timeout
+error when one of the inflight entries' wait time reaches the timeout line. It is
+responsible for ensuring the correctness of the target node ID and maintaining the state
+of the packages throughout the verification process.
+The scoreboard entry can record the routing path when added, and the routing path
+check is performed when each middle routers receive a package. In case of a mismatch,
+the routing monitor invokes the wrong routing path error. This component ensures that
+the routing path of the packets is maintained throughout the verification process.
+