Digital signal processor

Digital signal processor

A Digital Signal Processor (DSP) is a specialized microprocessor designed specifically for (real-time) digital signal processing. DSPs can also be used to perform general-purpose computation, but they are not optimised for this function.

Rather than general computations, DSPs usually have an instruction set (ISA) optimised for/by:

Multiply-accumulate (MAC) operations (good for all kinds of matrix operations).
Deep pipelining.
DMA processing.
Saturation arithmetic (i.e. figures do not "wrap around" from maximum positive values to minimum negative values but saturate at the max/min level.
Separate program and data memories.
Most DSPs are fixed-point, however, floating point DSPs are common for more demanding applications.
Specialized instructions for modulo addressing in ring-buffers and for FFT cross-referencing.

DSP functionality can also be realised using FPGA chips. Present-day general-purpose microprocessors have ideas and influences from digital signal processors, such as the MMX extensions in the Intel IA-32 architecture.

History

The first successful DSP was the NEC µPD7710 presented in 1980 soon followed by the AT&T DSP1 in the same year.

The first DSP produced by Texas Instruments, the TMS32010 presented in 1982, was an even bigger success.