In the document SPRS691E, Figure 2-17 C66x DSP Device Nomenclature (including the TMS320C6678), I can see a definition for Device Speed Range.
According to that, the device I'm currently using, whose nomenclature is TMS320C6678CYP YB20-64ZDH59, should has a speed range at 1.0GHz.
But on the chip surface, upper right corner, a sign "A1.25GHz" is printed.
Then what the real speed range is for the device I'm using? Can I get it runnint at 1.25GHz?