Format conversion system

Abstract

A format conversion system for use in digital systems converts digital data words from a fixed point format to a floating point format and vice versa. A two's complement circuit tests the sign bit of a first fixed point digital data word and provides the complement if the word is negative. A code establishing circuit receives the first fixed point digital data word or its complement, detects the number of O's to the left of the most significant one bit and establishes a first code representative thereof. A second code establishing circuit receives the exponent of a first floating point digital data word and provides a second code representative thereof. A mantissa/fixed point determining circuit receives either the first fixed point digital data word, or the mantissa in reverse order, of the first floating point digital data word. The first code controls the mantissa/fixed point determining circuit to effectively move a radix point to the left in the first fixed point digital data word to form the mantissa of a second floating point digital data word. The second code controls the mantissa/fixed point determining circuit for moving the radix point to the left in the reverse order mantissa of the first floating point digital data word. This reverse order word is reversed again in a reversing circuit to provide a second fixed point digital data word. The reversing operation effectively moves the radix point to the right. An exponent determining circuit interprets the first code and provides the exponent associated with the mantissa of the second floating point digital data word, the exponent and the mantissa being combined in a combining circuit.