The following figure illustrates the anatomy of a two-dimensional lookup table. Vectors or breakpoint data sets and an array, referred to as table data, constitute the lookup table.
Each breakpoint data set is an index of input values for a particular dimension of the lookup table. The array of table data serves as a sampled representation of a function evaluated at the breakpoint values. Lookup table blocks use breakpoint data sets to relate a table's input values to the output values that it returns.