The role of occam in the design of the IMS T800

This paper describes how ’correct’ microcode can be produced through the use of mathematical logic and formal design methods. The use of these techniques to derive correct microcode for the IMS T800 floating point transputer from a mathematical specification is discussed. This experience on the IMS T800 has shown that this approach provides the opportunity to produce designs with a higher certainty of correctness in significantly less time as compared with ’traditional’ design techniques. These techniques are currently being applied to the construction of correct specifications at the hardware description language level. This work is attempting to incorporate mathematical logic and formal design methods into the INMOS CAD system so that their use becomes the standard way of producing correct VLSI devices.