A CMOS mainframe processor with 0.5- mu m channel length

A processor chip set with IBM/370 architecture is implemented on five CMOS VLSI chips containing 2.8 million transistors with an effective channel length of 0.5 mu m. The chip set consists of the instruction and the fixed-point processor, two cache chips with 16 KB of data and instructions, and the floating-point processor. The chips are implemented in a 1.0- mu m technology with three layers of metal. An automatic design system based on the sea-of-gates technique and the standard cell approach was used. The worst-case operating frequency of the chip set is 35 MHz (typically 50 MHz). Four chips of the processor are packaged on a ceramic multichip module. Level-sensitive scan design, built-in self-test, and parity check guarantee high test coverage and reliability.<
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