Data-processing systems and methods include a rendering device which renders documents based upon the timing and duration of a laser beam associated with particular pixel data. Additionally, a controlling mechanism for controlling and adjusting the particular pixel data can be provided, wherein the controlling mechanism is subject to pixel clock signal in order to optimize a performance of the rendering device under varying rendering parameters and thereby enhance the quality of data rendered via the rendering device. Such a controlling mechanism can be implemented as a programmable phase locked loop circuit to which a pixel clock signal and a frequency are applied in order to provide at least one output signal for controlling the laser beam.