Patent ID: 6218858
Filing Date: 2001-04-17
Classification: H03K

Abstract:
An apparatus comprising:first means for receiving data at a pin or external connection pad on a field programmable gate array using an input circuit which can be programmed to be compatible with either single-ended or differential input signals having logic 1 and logic 0 voltage levels and reference levels which are characteristics of a selected one of the TTL, GTL, GTLP, LPECL, or LVDS circuit families and converting said input signals to logic levels which are used in said field programmable gate array, said first means also having inputs for receiving control signals generated from programming bits which control whether said first means functions to convert TTL, GTL, GTLP, LPECL or LVDS format single-ended or differential input signals to logic signals at levels compatible with the internal circuitry of said field programmable gate array;second means for receiving data generated within said field programmable gate array at logic levels used in said field programmable gate array and converting the logic levels of said data generated within said field programmable gate array to output data for driving said pin or external connection pad on a field programmable gate array, said output data having logic levels compatible with any of the TTL, GTL or GTLP circuit families, said second means being programmable by means of receiving input signals generated from programming bits said input signals controlling whether said second means functions to convert said logic levels of said data generated in said field programmable gate array to output data having logic levels and current source and sink characteristics compatible with a selected one of the TTL, GTL or GTLP circuit families; andenabling means within said first means and said second means for receiving said control signals generated from said programming bits and controlling said first means so as to define which type of input circuit said first means is to be and controlling said second means to determine which type of driver said second means is to be.