Hello,
There's no C compiler for any SigmaDSP. Among other reasons, this is because these are primarily streaming audio processors for which not every C construct can be implemented. For example, branching and looping are commonplace in C code, yet older-generation SigmaDSPs (ADAU1701, etc.) cannot even execute a branch. Although the latest-generation Sigma 300 chips (ADAU145x) are far more capable, the whole idea behind SigmaDSP is the SigmaStudio IDE. SigmaStudio compiles the engineer's graphic flow diagram directly to the target chip's machine code. You could say that SigmaDSPs and SigmaStudio were made for each other. Thus any port must be performed manually, if possible at all.
Best regards,
Bob