Here it means SIMD/vectorized operations. Arm Cortex M4F with DSP extensions can do 4 operations on 8 bit data. For traditional signal processing (FIR/IIR filt

Here it means SIMD/vectorized operations. Arm Cortex M4F with DSP extensions can do 4 operations on 8 bit data. For traditional signal processing (FIR/IIR filters) dedicated opcode for multiply accumulate is also common, since it is used so much. Saturated add/subtract is another typical 'DSP' kind of feature. EDIT: such opcodes exists on many CPU/GPUs also, but we are talking sub-milliwatt capable devices here.