Embedded & SoC architecture Communication protocol
VisualSim FlexRay Modeling library enables designers to model the FlexRay protocol accurately and to conduct network design trade-offs. It also enables a system designer to construct models of complex standard and non-standard FlexRay topologies.The FlexRay Bus Model is based on the FlexRay ProtocolSpecification V2.1 (2005).
Physically, a token ring network is wired as a star, with Multistation Access Units (MAUs) in the centre, arms out to each station and the loop going out and back through each. A MAU could be presented in the form of a hub or a switch; since token ring has no collisions, many MAUs were manufactured as hubs. Some of the parameters used are as follows:
VisualSim Token Ring provides nodes or stations, and Media Access Control protocol (MAC) messages to direct the traffic. The designer can modify the pre-built fairness algorithm with their own implementation by replacing the arbitration block in the template. This can be used to evaluate the traffic flow improvement and the elimination of congestions in the traffic scenarios. Different classes of service has been implemented including committed information rate (CIR), mix of both a CIR and an excess information rate (EIR; which is subject to fairness queuing) and best effort traffic, utilizing whatever bandwidth is available.
Token ring networks use the token passing access method, which is based on a small frame called a token that circulates a ring-shaped media in a logical direction when devices are idle. To transmit, the device must seize the token. A token ring network is a local area network (LAN) in which all computers are connected in a ring or star topology and a binary digit- or token-passing scheme is used in order to prevent the collision of data between two computers that want to send messages at the same time. The token ring protocol is the second most widely-used protocol on local area networks after Ethernet. The IBM Token Ring protocol led to a standard version, specified as IEEE 802.5. Both protocols are used and are very similar.