We introduce a scheme to simplify a multi-valued network using redundancy removal techniques. Recent methods [1], [2] for binary redundancy removal avoid the use of state traversal. Additionally, [2] finds multiple compatible redundancies simultaneously. We extend these powerful advances in the field of binary redundancy removal to perform redundancy removal for multi-valued networks.First we perform a one-hot encoding of all the multi-valued variables of the design. Multi-valued variables are written out as binary variables, using this one-hot encoding. At the end of this step, we have a binary network which is equivalent to the multi-valued network modulo encoding.Next, binary redundancy removal is invoked on the resulting network. In case a binary signal s_i is determined to be stuck-at-0 redundant, this means that the multi-valued signal s can never take on a value i. Further, if the binary signal s_i is determined to be stuck-at-1 redundant, this means that the multi-valued signal s takes on a constant value i. All redundant binary signals are recorded in a file. The original multi-valued network is modified based on the binary redundancies thus computed.Initial experiments using this technique show a 10-20\% reduction in the size of the multi-valued description.[1] "Sequential Optimization without State Space Exploration" Mehrotra, Qadeer, Singhal, Brayton, Sangiovanni-Vincentelli, Aziz. ICCAD 97. [2] "Identifying Sequential Redundancies without Search", Iyer, Long, Abramovici. DAC 96.
Citation:
Sunil P Khatri, Robert K Brayton, Alberto Sangiovanni-Vincentelli, "Sequential Multi-Valued Network Simplification using Redundancy Removal," vlsid, pp.206, 12th International Conference on VLSI Design - 'VLSI for the Information Appliance', 1999