Parallel Architecture Core (PAC) - the First Multicore Application Processor SoC in Taiwan Part I: Hardware Architecture & Software Development Tools

In order to develop a low-power and highperformance SoC platform for multimedia applications, the Parallel Architecture Core (PAC) project was initiated in Taiwan in 2003. AVLIW digital signal processor (PACDSP) has been developed from a proprietary instruction set with multimedia-rich instructions, a complexity-effective microarchitecture with an innovative distributed & ping-pong register organization and variable-length VLIWencoding, to a highly-configurable soft IP with several successful silicon implementations. A complete toolchain with an optimizing C compiler has also been developed for PACDSP. A dualcore PAC SoC has been designed and fabricated, which consists of a PACDSP core, an ARM9 core, scratchpad memories, and various on-chip peripherals, to demonstrate the outstanding performance and energy efficiency for multimedia processing such as the real-time H.264 codec. The first part of the two introductory papers of PAC describes the hardware architecture of the PACDSP core, its software development tools, and the PAC SoC with dynamic voltage and frequency scaling (DVFS).