Novel test selectors have demonstrated their effectiveness in accelerating the closure of functional coverage for various industrial digital designs in simulation-based verification. The primary advantages of these test selectors include performance that is not impacted by coverage holes, straightforward implementation, and relatively low computational expense. However, the detection of stimuli with novel temporal patterns remains largely unexplored. This paper introduces two novel test selectors designed to identify such stimuli. The experiments reveal that both test selectors can accelerate the functional coverage for a commercial bus bridge, compared to random test selection. Specifically, one selector achieves a 26.9% reduction in the number of simulated tests required to reach 98.5% coverage, outperforming the savings achieved by two previously published test selectors by factors of 13 and 2.68, respectively.

This paper describes the verification of two versions of a bridge between two on-chip buses. The verification was performed just as the Infineon Technologies Design Centre in Bristol was introducing pseudo-random testing (using Specman) and property checking (using GateProp) into their verification flows and thus provides a good opportunity to compare these two techniques with the existing strategy of directed testing using VHDL bus functional models.

Let g be the genus of the Hermitian function field $H/{\mathbb F}_{q^2}$ and let $C_{\cal L}(D,mQ_{\infty})$ be a typical Hermitian code of length n. In [Des. Codes Cryptogr., to appear], we determined the dimension/length profile (DLP) lower bound on the state complexity of $C_{\cal L}(D,mQ_{\infty})$. Here we determine when this lower bound is tight and when it is not. For $m\leq \frac{n-2}{2}$ or $m\geq \frac{n-2}{2}+2g$, the DLP lower bounds reach Wolf's upper bound on state complexity and thus are trivially tight. We begin by showing that for about half of the remaining values of m the DLP bounds cannot be tight. In these cases, we give a lower bound on the absolute state complexity of $C_{\cal L}(D,mQ_{\infty})$, which improves the DLP lower bound. Next we give a "good" coordinate order for $C_{\cal L}(D,mQ_{\infty})$. With this good order, the state complexity of $C_{\cal L}(D,mQ_{\infty})$ achieves its DLP bound (whenever this is possible). This coordinate order also provides an upper bound on the absolute state complexity of $C_{\cal L}(D,mQ_{\infty})$ (for those values of m for which the DLP bounds cannot be tight). Our bounds on absolute state complexity do not meet for some of these values of m, and this leaves open the question whether our coordinate order is best possible in these cases. A straightforward application of these results is that if $C_{\cal L}(D,mQ_{\infty})$ is self-dual, then its state complexity (with respect to the lexicographic coordinate order) achieves its DLP bound of $\frac {n}{2}-\frac{q^2}{4}$, and, in particular, so does its absolute state complexity.

We study Reed-Muller codes and "Berman" codes as Abelian codes. We show that the duals of Berman codes and Reed-Muller codes can be considered as belonging to the same family of Abelian codes. We also determine the minimum distance and state complexity of the duals of Berman codes. Each of the classical parameters generalizes that of Reed-Muller codes in the obvious way, but the state complexity does not. We conclude by comparing the asymptotic behavior of the state complexity of the duals of Berman codes with that of the obvious generalization of the state complexity of Reed-Muller codes.

We answer a problem posed by Etzion and Vardy (1998) by showing that a binary code of length N=2(m)-2 with 2(N-m) codewords and minimum distance three can always be lengthened to form a perfect code of length 2(m-1).