Selection and Solution Guides

Application Notes

Engine Knock Detection Using Spectral Analysis With TMS320C25 or TMS320C30 DSPs


An efficient method of detecting combustion engine knock is using spectral analysis. The detection process algorithm adapts to a no-knock reference at varying speeds and loads by using multiple frequencies. This document presents an problem overview, current technology, and two implementation examples are given to aid in the development of system specific hardware and software. The first system is based on the 32-bit floating-point TMS320C30 DSP with software written in C. The second is production oriented using a TMS320C25 16-bit fixed-point DSP and assembler software. The appendix contains the code for each implementation.