Each data I/O trace connects to an 0805 SMT pad with access to GND for a customizable load. Large pads were chosen for ease of access and the option to compose a load out of multiple, smaller, SMT components if desired. A 0 Ω resistor is located in series with each I/O line. Both the SMT pad and resistor can be used and modified for RC load tests, propagation delay, rise or fall time adjustments, input filtering, and so forth. Figure 2-4 shows the SMT pad and 0 Ω resistor locations. Pull down pads are boxed and labeled Load with the bottom pad being referenced to GND. Each input and output is fitted with individual GND pins for ease of use with differential probes.