A logic analyzer (occasionally called a logical analyzer) is a laboratory test instrument designed to display and evaluate digital signals. The device works in a manner similar to the way that an oscilloscope displays and facilitates the analysis of analog signals. A logic analyzer allows engineers to design, optimize, and debug the hardware in prototype digital systems, and can help technicians find and fix problems in malfunctioning systems. In its most basic form, a logic analyzer captures and displays a sequence of digital events. Once the data are captured, they can be rendered as graphical images, state listings, or decoded traffic. Some analyzers can compare each captured data set to a previously recorded data set, and let the operator know whether or not the two data sets are identical. The functions of a digital storage oscilloscope with a logic analyzer are combined in a lab instrument known as a mixed-signal oscilloscope. This instrument can display multiple analog and digital signals one above the other, along a common horizontal time axis