CS6257 Datasheet, ISSI

CPU  RISC core with unified DSP instructions 125MIPS  Clock sources
* Crystal Oscillator 8MHz
  – 16MHz
* Programmable PLL up to 125MHz  32-Bit W.

The CPU is MIPS-X core with enhanced DSP instructions and accelerator and can run up to 125MHz. There are on-chip 64KB .