Fixed-Bias and Variable-Bias Random Pattern Generator
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
With the increased amount of testing using randomly generated patterns, there will be circuits where biased random patterns are more efficient than patterns containing an equal distribution of 1's and 0's. Using the circuit illustrated in Fig. 1, a random pattern can be generated with a biased distribution of 1's and 0's. To accomplish this, a number of bits are selected from a random pattern generator, such as a Linear Feedback Shift Register (LFSR), the bits being either ANDed or ORed together depending on whether the pattern is to be biased toward 0 or 1. Table 1 illustrates the biasing for n=2 through 6: Alternatively, referring to Fig. 2, the 'n' number of bits (A) selected from the random pattern generator are compared with n bits (B) from the bias control.