Cost-Efficient Synthesis for Sequential Circuits Implemented Using Embedded Memory Blocks of FPGA's

Modern FPLD devices have a very complex structure. They combine PLA-like structures as well as FPGA's and even memory-based structures. However, the lack of an appropriate synthesis method does not allow the features of the modern FPLD's to be fully exploited. In this paper, an important problem of state assignment for an FSM as an extension of the previous research on ROM-based FSM implementation is presented. We pinpoint the sources of additional optimization of the functional decomposition and relate them to the state encoding conditions. The method is based on a reduction of a state assignment problem to a graph coloring problem. To this end, the so called multi-graph of incompatibility of memory T-words is applied. As a result, a new design technique for implementation of sequential circuits using embedded memory blocks of FPGA's has been developed. Preliminary experimental results are extremely encouraging.