Circuit to Determine Number of Leading Zeros in a Binary String
Original Publication Date: 1985-Jul-01
Included in the Prior Art Database: 2005-Feb-19
A technique is described whereby the number of leading zeros in a binary string is determined in a fast and efficient manner. This determination is particularly useful in applications such as in floating point normalization operations. The circuit, as shown in the figure, illustrates the operation of determining the number of leading zeros in a ten-bit string. This method may be used on longer strings, as required. AND gates A0 to A9 determine the number of leading zeros from the 10-bit binary string register 10. If there are no leading zeros, no output will be present at output lines Z1 to Z10. If, for example, positions 8 and 9 of the 10-bit string are zeros, Z2 will indicate, through AND gate A8, that there are two leading zeros. To convert this information into binary form, OR gates 11 are used.