Performance evaluation of a microprocessor with on-chip DRAM and high bandwidth internal bus

The M32R/D is a 32-bit microprocessor with on-chip 2M-byte (16M-bit) DRAM. It has a 32-bit RISC CPU, 32-bit/spl times/16-bit multiply and accumulator, 2M-byte DRAM, 2K-byte cache memory, and a memory controller. The CPU, DRAM, and cache memory are connected with a 128-bit 66.6MHz internal bus. This wide internal bus allows high speed transfer of instructions. The use of a 128-bit bus resulted in a 13% improvement in performance as compared with 32-bit bus.