METHOD FOR HIGH SPEED BCD-TO-BINARY CONVERSION.

The BCD-to-binary design proposed as a high speed coded number converter can translate an 8-digit BCD number into a 27-bit binary number in 60 ns. The method is sufficiently fast to complete the process within one computer memory cycle of any available digital computer. High speed conversion of the number provides assurance that the input data to the computer will be in binary form at any time computer instructions request it. The design architecture was implemented using Schottky-clamped TTL integrated circuits. A less costly configuration can be obtained by using standard TTL integrated circuits such as the 74181 arithmetic logic unit and 74182 carry-look-ahead generator but results in a sacrifice of conversion speed. When standrd TTL logic circuits are usedthe converter can be expected to convert an 8-digit BCD number into a 27-bit binary number in approximately 150 ns, which is sufficiently fast for many applications and provides a saving of initial component costs.