Dual Mode CircLink™ Controller
Datasheet
1.2
About TMC2074
The TMC2074 network controller is CircLink technology’s flagship product. The TMC2074’s flexibility and
rich feature set enable a high-reliability and high-performance, real-time and control-oriented network
without the cumbersome middle layer protocol stacks and complex packet prioritization schemes typically
required.
TMC2074 operates at network data transfer rates up to 5 Mbps. Its embedded 1 kByte RAM can be
configured into a maximum of 32 pages to implement a 31-node network where each node in the network
has the same local memory.
The TMC2074 has two operational modes: “Peripheral Mode” and “Standalone Mode”. It can operate with
or without the existence of a system CPU on a network node. In Peripheral Mode, the TMC2074 has two
selectable communication modes, “Free Format Mode” and “Remote Buffer Mode”. Free Format mode,
retained from ARCNET, is “packet oriented” communication. Remote Buffer mode communication is a
CircLink-specific feature, and is a token oriented communication, which includes automatic data
transmission when the token arrives.
The TMC2074 has a flexible 8-bit or 16-bit databus to interface various CPU types including X86, 68XX,
and SHX with multiplexed or non-multiplexed address/data. When operating in Peripheral mode, the
TMC2074 has 8-bit programmable I/O available. When operating in Standalone mode, the TMC2074’s I/O
configuration is16-bit. The TMC2074 also integrates a 3-port hub (two ports for external connection) to
accommodate various network topologies (Bus, Star, etc.) and combinations.
SMSC TMC2074
Page 7
Revision 0.1 (03-29-06)
DATASHEET
SMSC [ SMSC CORPORATION ]
