A floating point radix 2 shared division/square root chip

Abstract

This paper presents the architecture and implementation of a full-custom 1.2 micron CMOS VLSI chip that executes a shared division/square root algorithm operating on mantissas (23-b in length) of single precision IEEE 754 std. floating point numbers. The division and square root algorithms used in this implementation are the radix 2 signed digit based digit-by-digit schemes. These two algorithms perform quotient/root digit selection using two most-significant digits of the partial remainder and are hence faster than other similar previously proposed radix 2 shared division/square root schemes. This chip runs at a clock rate of about 66 MHz at 5.0 V (from simulations) and requires 29 cycles per divide/square root operation from the time the operands are provided at its pin inputs.