A Multichip CMOS RISC Processor with Low-Voltage Swing Inputs and Outputs

A high-speed, multichip RISC processor with terminated offchip interconnects for no reflections required a differential output driver using a low-voltage swing. It achieved a propagation delay under 1.7 ns. A low-voltage swing input buffer was designed with a set-up time of 0.4 ns in differential mode and 0.75 ns in single-ended mode. A custom ceramic 299-pin PGA package was designed with controlled impedance lines and shield planes to reduce crosstalk.