HARP chip: a 600 Mflops application-specific LSI for astrophysical N-body simulations

Describes an application-specific LSI, the HARP (Hermite AcceleratoR Pipe) chip, which will he used in GRAPE-4, a massively-parallel special-purpose computer for astrophysical N-body simulations. The HARP chip calculates the gravitational interaction between particles. It consists of 15 floating point arithmetic units and one unit for function evaluation. The HARP chip performs about 20 floating point operations per clock cycle and works at 30 MHz in the worst case. Therefore, the performance of the HARP chip exceeds 600 Mflops. It is made using 1.0 /spl mu/m CMOS cell-based ASIC (LSI Logic, LCB007). The die size is 14.6 mm/spl times/14.6 mm and the total Rate count is 95,000. The power consumption is 5W at operating voltage of 5 V. The authors have examined successful operations of the sample chip up to 50 MHz. GRAPE-4 will consist of about 2000 HARP chips using multi-chip modules. The peak speed of GRAPE-4 will exceed 1 Tflops even in the worst case, and will reach around 1.8 Tflops in the typical case.<>