A resource-shared VLIW processor architecture for area-efficient on-chip multiprocessing

We propose an area-efficient resource-shared VLIW processor (RSVP) for future leaky nm process technologies. It consists of several single-way independent processor units (IPUs) that share parallel processor resources. Each IPU works as a variable-way VLIW processor sharing the parallel resources according to priorities of given tasks. RSVP allocates shared parallel resources to the IPUs cycle by cycle. It can minimize the number of NOPs that waste power. The performance per power (P³) of a 4-parallel 4-way RSVP that corresponds to four 4way VLIWs is 3.7% better than a conventional 4-parallel 4-way VLIW multiprocessor in the current 90nm process. We estimate that the RSVP achieves 36% less leakage power and 28% better P³ in the future 25nm process. We have fabricated an RSVP test chip that contains two IPU and a shared resource equivalent to two 2way VLIWs in a 180nm process. It is functional at 100MHz clock speed and its power is 130mW.