ALU and Carry Circuit in Differential Cascode Current Switch Technology
Original Publication Date: 1983-May-01
Included in the Prior Art Database: 2005-Feb-07
The Arithmetic and Logic Unit (ALU) circuit provides Add, Subtract, AND, OR, Exclusive OR, Shift Right, Flush A and Flush B functions in Differential Cascode Current Switch (DCCS) technology. The height of DCCS trees is limited by semiconductor technology and circuit considerations. If differential transistor pairs are used throughout the tree, the height of the tree determines the maximum number of variables that may be present in any current path of the tree. This means that current flowing from the resistor to the current source should pass through a maximum of M devices, where M is 5 for existing 5-volt semiconductor processes.