Design of the PowerPC 604e(tm) Microprocessor

The PowerPC 604e microprocessor is a lower power, higher performance extension of the PowerPC 604TM microprocessor. The 604e doubles the cache size and tunes the performance of memory accesses compared to the original 604. The 604e has also added hardware support for misaligned data accesses when using little-endian byte ordering. The branch processing microarchitecture of the 604e has been somewhat enhanced. To assist sofnvare writers in tuning their code, the 604e has significantly enhanced its hardware performance monitor. These enhancements along with the process migration were done using the Somerset design methodology. This combination of enhancements along with changing to a faster, lower voltage silicon process have made the 604e the highest performance PowerPCTM microprocessor on the desktop.