DLL is used as a clock generator due to its stable operation and relatively simple design. Analog DLL has the advantages of lower phase offset and lower clock jitter than digital DLL. However, locking speed is slow in analog DLL. This paper proposes a dual edge triggered phase detector to enhance the locking speed of analog DLL and suggests a closed-form expression of locking speed which can co...

This paper analyzes the sources of jitter in a DLL and presents a behavioral model for fast DLL optimization. An algorithm to simulate the DLL in open loop is demonstrated. This procedure, together with the behavioral modeling, greatly reduces the simulation time of DLL when compared to the closeloop DLL simulation. In order to optimize the DLL performance, the dependence of the output jitter v...

Modern Chaff-like SAT solvers enhance plain backtracking (DLL) by Conflict-Driven Learning (CDL), including 1UIP-based Conflict-Directed Backjumping (CDB), Non-Chronological Backtracking (NCB), and 1UIP-based Conflict-Clause Recording (CCR). We show how to add these enhancements step-by-step to plain DLL to derive Chaff’s Conflict-Driven Learning algorithm, separately and independently of BCP, ...

Several homeobox-containing genes related to Drosophila Distal-less (Dll) have been isolated from a wide variety of organisms and have been shown to function as developmental regulators. While in Drosophila only one Dll gene has been described so far, in Vertebrates many components of the Dlx multigenic family have been characterized. This suggests that, during the evolution of the Chordate phy...

This study investigates the role of the homeobox gene Distal-less (Dll) in the development of the legs, antennae, and wings of Drosophila. Lack of Dll function causes a change in the identity of ventral appendage cells (legs and antennae) that often results in the loss of the appendage. Ectopic Dll expression in the proximal region of ventral appendages induces nonautonomous duplication of legs...

In the leg and wing imaginal discs of Drosophila, the expression domains of the homeobox genes aristaless (al) and Distal-less (Dll) are defined by the secreted signaling molecules Wingless (Wg) and Decapentaplegic (Dpp). Here, the roles played by al and Dll in patterning the legs and wings have been investigated through loss of function studies. In the developing leg, al is expressed at the pr...

This paper proposes a fast-locking digital delay-locked loop (DLL) with multiphase outputs using mixed-mode-controlled delay line (MCDL). The proposed DLL uses a dual-loop technique to control various MOS capacitors and an MOS resistor in the MCDL to improve locking time and reduce static phase error. The chip was fabricated using a 0.35 μm standard CMOS process with a 3.3 V supply voltage. The...

We present a strategy to examine the chromatin conformation of individual loci in specific cell types during Drosophila embryogenesis. Regulatory DNA is tagged with binding sites (lacO) for LacI, which is used to immunoprecipitate the tagged chromatin from specific cell types. We applied this approach to Distalless (Dll), a gene required for limb development in Drosophila. We show that the loca...

AB!3TRACT CDMA systems require synchronization between the received sequence and the locally generated sequence. This is done by means of a Delay-Lock Loop (DLL). The differential equation of an incoherent secondorder DLL has been programmed. The Mean Time to Lose Lock (MTLL) of the DLL is a very important design parameter. We have obtained this parameter by computer simulation and we are able ...