Patent ID: 7124161

Claim:
A circuit for calculating reciprocal values, comprising: an input for receiving input data, the input data being partitionable into a plurality of segments including a first segment and a second segment; a first look-up table coupled to the input, the first look-up table having stored therein first pre-calculated values, the first look-up table configured to receive the first segment and for providing a first respective one of the first pre-calculated values in response to the first segment; a first shifter circuit coupled to the first look-up table, the first shifter circuit configured to receive the first respective one of the first pre-calculated values and for generating a first shifted value by shifting the first respective one of the first pre-calculated values according to a relative position of the first segment within the input data; a second look-up table coupled to the input, the second look-up table having stored therein second pre-calculated values, the second look-up table configured to receive the second segment and for providing a second respective one of the second pre-calculated values in response to the second segment; a second shifter circuit coupled to the second look-up table, the second shifter circuit configured to receive the second respective one of the second pre-calculated values and for generating a second shifted value by shifting the second respective one of the second pre-calculated values according to a relative position of the second segment within the input data; and an output selector circuit for selecting one of the first shifted value and the second shifted value as an approximate reciprocal value of the input data.