Design and Implementation of 8-bit LFSR, Bit-Swapping LFSR and Weighted Random Test Pattern Generator: A Performance Improvement

Area-Efficient Error Detection Structure for Linear Feedback Shift Registers

“…Examples of hardware [28][29][30] and time [31,32] redundancy methods to detect undesirable faults are shown in Figures 2 and 3, respectively. In both figures, the black line corresponds to the conventional LFSR [10][11][12][13][14][15][16][17][18][19][20][21] and the dashed blue line indicates the additional hardware overhead. Because of the use of linear functions, LFSRs are widely employed in various fields [21][22][23][24][25][26][27].…”

“…Although the time redundancy technique [31,32] improves the reliability, it demands a latency that is two times longer than that of the conventional LFSR [10][11][12][13][14][15][16][17][18][19][20][21]. These examples indicate that the overheads resulting from the redundancy methods [28][29][30][31][32] are as high as those of the conventional LFSR [10][11][12][13][14][15][16][17][18][19][20][21] and the overhead becomes more severe when the length N of the generator polynomial G(x) is large. Recently, more advanced redundancy technique is introduced targeting for error detection/correction adders [33][34][35], which achieves error detection/correction using information redundancy.…”

“…The linear feedback shift register (LFSR) is one of the most widely used sequential logics, which produces the linear function of its previous state [10][11][12][13][14][15][16][17][18][19][20][21]. The conventional LFSR consists of shift registers and XORs, as shown in Figure 1.…”

“…Based on (1), the n-th shift register S n [i + 1] at the (i + 1)-th clock cycle is linearly updated by adding the (n − 1)-th shift register S n−1 [i] and Sn−1 [i] and n-th feedback signal gnF [i] at the i-th clock cycle. As a result, LFSRs can generate the linear functionality of the previous state according to the generator polynomial and feedback signal [10][11][12][13][14][15][16][17][18][19][20][21]. Because of the use of linear functions, LFSRs are widely employed in various fields [21][22][23][24][25][26][27].…”

“…As far as we searched, there are seldom recent literatures that describe the error detection/correction designs for LFSR implementation. Traditional redundancy methods [28][29][30][31][32] can be applied to LFSRs to attain a highly reliable design by duplicating the original LFSR [10][11][12][13][14][15][16][17][18][19][20][21] in terms of time and hardware. However, the overheads from the duplication are inevitable and they become a serious burden when the length of the generator polynomial is large.…”