DESIGN OF A CUSTOM ASIC INCORPORATING CAN™ AND 1 ...

ABSTRACT
The vast majority of today’s digital designs utilize custom ASICs (Application-Specific
Integrated Circuits) or gate arrays. In general, ASICs offer the lowest possible device power
consumption for implementing a given function. Each year the number of custom ASICs
designed increases, while the number of parts required for each design decreases. This is due in
part to the increasing use of FPGAs (Field Programmable Gate Arrays) and their ability to
provide a lower cost ASIC-based alternative for limited production designs.
This paper presents a VLSI (Very Large Scale Integration) design and simulation of a
custom ASIC incorporating two serial bus communication protocols, CAN (Controller Area
Network) and 1 – Wire®, and is targeted towards wearable medical technology and devices as
well as advanced vehicular technologies. In designing a custom communications interface
module, a number of technical and potentially challenging problems had to be addressed and
overcome. These include but are not limited to: combining a multimaster and a single-master
protocol, event-triggered and time-triggered control paradigms, differential communication
speeds, and messages by addressing and messages by IDs. By combining the low-cost and ease
of CAN-enabling almost any device with the variety of 1 – Wire® devices currently in-
production, the combinations of sensor networks is only limited by the creativity of the system
designer. Given the limited FPGA resources utilized by the design presented in this manuscript,
a low-cost ASIC could handle the data demands and provide the communications interface of
most any application for either market.
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