Xilinx, Inc.
Integrated circuit skew determination

Abstract:

Examples described herein provide determining skew of transistors on an integrated circuit. In an example, an integrated circuit includes a ring oscillator and first and second detector circuits. The ring oscillator includes serially connected buffers. Each buffer includes serially connected inverters that include transistors. A transistor of each buffer has a different strength of another transistor of the respective buffer. The first and second detector circuits are connected to different first and second tap nodes, respectively, along the serially connected buffers. The first detector circuit is configured to count a number of cycles of a reference clock that a cyclic signal on the first tap node is either a logically high or low level. The second detector circuit is configured to count a number of cycles of the reference clock that a cyclic signal on the second tap node is either a logically high or low level.