SHARC core clock frequency


Because of long lead times I'm interested in using some DSP components already in stock.  The specified DSP is a 500MHz rating, but the more easily available parts are 450MHz.  Is there a way to determine at run time which part is used so I can configure the CGU and not have to support two different branches of code?  For each part the IDCODE is the same; 0x228080CB.