Using differential data strobes in non-differential mode to enhance data capture window

Abstract

A data capture circuit includes strobes that track input data even when conditions arise that cause the differences in skew from interpreting data state ones and zeros. This is accomplished whether these skews arise from reference voltage variation, data pattern loading, power supply droop, process variations within the chip itself, or other causes. The differential input strobes of the data capture circuit are input into individual input buffers, each compared against a reference voltage individually, as well as a data input pin. The outputs from these buffers are maintained separate from each other all the way to the point where the input data is latched. In latching the input data, data ones are latched entirely based on input signals derived from a rising edge (both strobes and data), and zeros are latched entirely based on input signals derived from a falling edge (both strobes and data).