A 0.18 μm implementation of a floating-point unit for a processing-in-memory system

The Data-Intensive Architecture (DIVA) system incorporates Processing-In-Memory (PIM) chips as smart-memory coprocessors to a microprocessor. This architecture exploits inherent memory bandwidth both on chip and across the system to target several classes of bandwidth-limited applications. A key capability of this architecture is the support of parallel single-precision floating-point operations. Each PIM chip includes eight single-precision FPUs, each of which supports eight basic instructions and IEEE-754 compliant rounding and exceptions. Through block sharing and a hardware-efficient division algorithm, the resulting FPU is well-balanced between area and performance. This paper focuses on the novel divide algorithm implemented and documents the fabrication and testing of a prototype FPU based on standard cell methodology in TSMC 0.18 μm CMOS technology.