Features of DSP chip

A digital signal processor (DSP) is a microprocessor specially designed for fast real-time processing of digital signals such as audio, speech, image and radar data. Its main features are:

1. Hardware multiplier-accumulator (MAC): performs a multiplication and addition in one clock cycle, which is the basic operation in filters and FFT.
2. Harvard architecture: separate program and data memories and buses, so an instruction and data can be fetched at the same time. Many DSPs have two or more data buses.
3. Pipelining and parallel units: an ALU, multiplier and address generator work in parallel.
4. Special addressing modes: circular buffer addressing (for filters) and bit-reversed addressing (for FFT).
5. Zero-overhead looping: hardware loop counters repeat a block without time lost for branch instructions.
6. Fast on-chip memory: on-chip RAM and ROM, and DMA, for quick data transfer.
7. Fixed-point or floating-point arithmetic, with saturation arithmetic to avoid overflow errors.
8. Real-time operation: fast interrupt response and I/O interfaces (serial ports, ADC/DAC).
9. Low power consumption and low cost, suitable for embedded systems.

Examples: TI TMS320 series, Analog Devices ADSP, Motorola 56000.