General Description
About CircLink
The CircLink networking controller was developed for small control-oriented local network data communication based on ARCNET’s token-passing protocol that guarantees message integrity and calculatable maximum delivery times.
In a CircLink network, when a node receives the token it becomes the temporary master of the network for a fixed, short period of time. No node can dominate the network since token control must be relinquished when transmission is complete. Once a transmission is completed the token is passed on to the next node (logical neighbor), allowing it to be come the master.
Because of this token passing scheme, maximum waiting time for network access can be calculated and the time performance of the network is predictable or deterministic. Industrial network applications require predictable performance to ensure that controlled events occur when required.

PRODUCT FEATURES
◾ Low Power CMOS, 3.3 Volt Power Supply with 5
   Volt Tolerant I/O
◾ Supports 8/16-Bit Data Bus
   − Both 86xx and 68hxx Platforms
◾ 1K On-chip Dual Port Buffer Memory
   − Sequential I/O Mapped Access
◾ Enhanced Token Passing Protocol from ARCNET
   − Maximum 31 Nodes per Network
   − Token Retry Mechanism
   − Maximum 256 Bytes per Packet
   − Consecutive Node ID Assignment
◾ Memory Mirror
   − Shared Memory within Network
◾ Network Standard Time
   − Network Time Synchronization
   − Automatic Time Stamping
◾ Coded Mark Inversion
   − Intelligent 1-Bit Error Correction
   − Magnetic Saturation Prevention
◾ Single Operation Mode
   − Supports Only Peripheral (Host) Mode Operates
      with MCU
◾ Supports 8 Bit Programmable General Purpose
   I/O
◾ Dual Communication Modes (with Peripheral
   Mode)
   − Free Format Mode
   − Remote Buffer Mode
◾ 3 Port Hub Integrated
   − 1 Internal and 2 External
◾ Flexible Topologies
   − Bus, Star, and Tree
◾ Low-Cost Media can be Used
   − RS485 Differential Driver
◾ Fiber Optics and Twisted Pair Cable Supported
◾ 100-Pin TQFP Package; Green, Lead-Free
   Package also Available
◾ Temperature Range from 0 to 70 Degrees C