Method of compressing lookup table for reducing memory, non-linear function generating apparatus having lookup table compressed using the method, and non-linear function generating method
AssigneeSamsung Electronics Co., Ltd.
InventorHeon-Soo Lee
Life of this patent
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Abstract
In a method of compressing a lookup table for reducing memory, a non-linear function generating apparatus having a lookup table compressed using the method, and a non-linear function generating method, X-coordinates of the non-linear function are separated into a plurality of sections including steps that have predetermined step sizes. Y-coordinate values corresponding to X-coordinate values are extracted for each step: The Y-coordinate values are stored in predetermined addresses in a memory, wherein the step sizes are different according to the sections. In this manner, memory capacity occupied by the lookup table is reduced.
Claims20
A method of compressing a lookup table of an apparatus for generating a non-linear function, the method comprising:
- separating X-coordinates of the non-linear function into a plurality of sections including steps that have predetermined step sizes;
- extracting Y-coordinate values corresponding to X-coordinate values for each step;
- and
- storing the Y-coordinate values in predetermined addresses in a memory,
- wherein-the step sizes are different according to the sections.
An apparatus for generating a non-linear function, the apparatus comprising:
- an analyzer calculating and outputting analysis information including addresses based on an input X-coordinate value;
- a memory including a lookup table in which Y-coordinate values corresponding to the X-coordinate values for each step of the non-linear function, the y-coordinate values being separated into a plurality of sections including the steps having predetermined step sizes and being stored in predetermined addresses, the memory outputting the Y-coordinate values corresponding to the addresses;
- and
- a calculator calculating and outputting an approximate Y-coordinate value corresponding to the input X-coordinate value using analysis information and the Y-coordinate values corresponding to the addresses,
- wherein the step sizes are different according to the sections, the analysis information includes section information and step information of the section where the input X-coordinate value is included, the step sizes, and an approximate X-coordinate value of the input X-coordinate value, and the addresses include the address of the step in which the input X-coordinate value is included and the address of the subsequent step.
A non-linear function generating method using an apparatus for generating a non-linear function, wherein the apparatus includes a lookup table in which Y-coordinate values corresponding to X-coordinate values of each step of the non-linear function separated into a plurality of sections including steps with predetermined step sizes are stored in predetermined addresses, the method comprising:
- calculating section information and step information using an input X-coordinate value;
- calculating an address using the section information and the step information;
- obtaining a Y-coordinate value corresponding to the address using the lookup table;
- calculating an approximate X-coordinate value of the input X-coordinate value using the address;
- calculating step size of the corresponding section using the section information;
- and
- calculating and outputting an approximate Y-coordinate value of the Y-coordinate value corresponding to the input X-coordinate value using the approximate X-coordinate value of the X-coordinate, the Y-coordinate value corresponding to the address, and the step size.
Dependencies are inferred from the claim text.