Abstract: A spreading system according to an embodiment of the invention spreads two data signals. The system produces a filtered signal that is based on one of the data signals and an output signal that is based on both of the data signals. In one example, a spreading system is used to perform QPSK spreading of two data signals, including separate processing of the two data signals, in a practical manner. Such separate control may include filtering and/or gain control.

Abstract: The present invention is a novel and improved method and circuit for digital signal processing. One aspect of the invention calls for the use of a variable length instruction set. A portion of the variable length instructions may be stored in adjacent locations within memory space with the beginning and ending of instructions occurring across memory word boundaries. Furthermore, additional aspects of the invention are realized by having instructions contain variable numbers of instruction fragments. Each instruction fragment causes a particular operation, or operations, to be performed allowing multiple operations during each clock cycle. Thus, multiple operations are performed during each clock cycle, reducing the total number of clock cycles necessary to perform a task. The exemplary DSP includes a set of three data buses over which data may be exchanged with a register bank and three data memories.