Efficient Code Synthesis from Function Blocks

Abstract

This chapter presents techniques for automatically generating code from IEC 61499 function blocks. While software synthesis from function blocks is in itself not new, the generation of efficient code from it is challenging. This is particularly so for the synthesis of distributed programs, as most existing techniques rely on features of a specific run-time environment to facilitate this. Instead of a run-time environment, this chapter proposes a globally asynchronous locally synchronous (GALS) model to implement distributed function block systems. This model provides an abstract way to view communication between function blocks without implying any particular implementation yet. This abstraction can then be subsequently refined to obtain various implementations with different trade-offs. This is done using an approach that is fully compatible with the standard’s notion of communication function blocks, which abstract underlying communication mechanisms from the application. For centralized programs, the synthesized code may be fully synchronous, which results in very efficient deterministic programs.