Specialised CPUs for fast multiply-accumulate operations.
DSPs have hardware multiply-accumulate (MAC), circular addressing, zero-overhead loops and SIMD for filters, FFTs and control loops. Many MCUs now include DSP extensions. Use fixed-point libraries (CMSIS-DSP) and optimise data placement.
A 64-tap FIR filter needs 64 MACs per sample.
DSPs are designed for the multiply-accumulate operations at the heart of filters and transforms, so they process signals far faster than general CPUs.
Specialised CPUs for fast multiply-accumulate operations.
DSPs are designed for the multiply-accumulate operations at the heart of filters and transforms, so they process signals far faster than general CPUs.
Multiplying two numbers and adding the result to a running sum, which is the basic step of a digital filter.
Many have DSP instructions and fast multipliers, which handle many signal tasks without a separate chip.
Typical applications include running a real-time audio filter on a dedicated DSP chip, computing an FFT on a radar signal in real time and implementing a motor control algorithm with fast multiply-accumulate operations.
Study "TinyML" first (topic 89 of 104 in Electronics & Embedded). It covers the groundwork this topic builds on.
FIR filter is a MAC loop. Harvard architecture. Saturating arithmetic.
A 64-tap FIR filter needs 64 MACs per sample.
The next topic is "Fixed-point arithmetic", which builds directly on this one.
It is classed as Advanced in Electronics & Embedded (topic 90 of 104). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Electronics & Embedded.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.