SuperH (SH) 64-Bit RISC Series SH-5 System Architecture, Volume ...

PRELIMINARY DATASuperHyway architecture 11A simple implementation containing a packet-router, two single-ported SH-5modules and one double-ported SH-5 module is illustrated in Figure 4.The SH-5 eval chip implementation of the SuperHyway packet-router architectureis described in Section 2.5: SH-5 SuperHyway implementation on page 22.2.2.1 PacketsSH-5 moduleSH-5 moduleSH-5 modulePortPortPortPortSuperHywaypacket-routerFigure 4: A simple implementationThe packet is the unit of data transfer through the SuperHyway. Communicationbetween SH-5 modules is achieved by the exchange of packets between those SH-5modules.A packet is composed of fields. Each field has a number of possible values tocharacterize that packet. Every packet contains a destination field which is used todetermine which SH-5 module the packet should be routed to. Further informationon packets is given in Section 2.2.6: SuperHyway protocol on page 16. In particular,packets contain a field that indicates the type of access made by that packet.D R A FTEach packet journey is associated with a source SH-5 module and a destinationSH-5 module. The source sends a packet over a port into the packet-router. Thepacket-router arranges for the packet to be routed to a port connected to thedestination. The destination then receives this packet over that port from thepacket-router. It is possible for the source and destination to be the same SH-5module.05-SA-10001 v1.0SuperH, Inc.SH-5 System Architecture, Volume 1: System