ANALOG DEVICES Using C To Implement Interrupt-Driven Systems On ADSP-219x DSPs Manual

About this manual

This document is an Engineer-to-Engineer Note (EE-88) from Analog Devices regarding the use of their DSP components and development tools. It specifically addresses the procedure for initializing variables in C using the 21xx C compiler, noting that this process is more complex than using assembly code. The note explains that to initialize variables in C for the 21xx family of DSPs, it is necessary to define arrays in an external assembly module, declare them as ".global" in the assembly code, and then declare them as "extern" in the C code.

What's inside

• Overview
• Initializing Variables in C
• External Assembly Module
• FFT Example Code
• Command Lines

Frequently asked questions

What data format must the initialization files use?

The files containing hex values for initializing variables must be in 1.15 data format.

How many data points does the example FFT code process?

The provided example code performs an FFT and inverse FFT on an array of 256 data points.

What causes discrepancies between the input and output signals in the example?

Discrepancies are caused by the limited resolution of the 21xx DSP family.