A zero-overhead self-timed 160-ns 54-b CMOS divider

The authors describe the design of a custom integrated circuit for the arithmetic operation of division. The chip uses self-timing to avoid the need for high-speed clocks and directly concatenates precharged function blocks without latches. Internal stages form a ring that cycles without any external signaling. The self-timed control introduces no serial overhead, making the total chip latency equal just the combinational logic delays of the data elements. The ring's data path uses embedded completion encoding and generates the mantissa of a 54-b (floating-point IEEE double-precision) result. Fabricated in 1.2- mu m CMOS, the ring occupies 7 mm/sup 2/ and generates a quotient and done indication in 45 to 160 ns, depending on the particular data operands.< >