The High-Definition Multimedia InterfaceTM (HDMI) I/O standard utilizes a 3.3V terminated transition minimized differential signaling (TMDS) standard. Although TMDS signaling can be received natively using the Spartan®-6 FPGA SelectIOTM interface, using the GTP transceivers can increase performance. The focus of this application note is on techniques to enable systems using the higher bandwidth capability of GTP receivers.
It is possible to use an external passive network to adapt the GTP transceivers to receive a signal that is compliant with HDMI technology. In this application note, two alternative passive networks are presented, analyzed, and compared from both a theoretical and a practical point of view. Both networks were tested on a custom development board to explore their signal integrity limits and to confirm theoretical expectations.
Although the results are general, the chip-to-chip use case is the one primarily considered in this application note. The target data rate used for HDMI is 1.45 Gb/s.