Analog Devices ADSP-21160 SHARC Processors Implementing Overlays EE-284

About this manual

This document discusses the implementation of software overlays on ADSP-21160 SHARC processors, which are used when a processor lacks sufficient internal memory for all application data and code. It describes the external memory packing of the ADSP-21160 and demonstrates the software overlay technique using example code on the ADSP-21160 EZ-KIT Lite board. The note also references previous documentation on using memory overlays with SHARC processors.

What's inside

• Introduction
• Overlays on SHARC Processors
• Overlays on ADSP-21160 SHARC Processors
• Packing Method in Visual DSP++
• VisualDSP++ Support
• Overlay Manager with DMA No Packing - Example
• Linker Definitions
• Overlay Manager with DMA Without Packing

Frequently asked questions

What is the purpose of overlays on ADSP-21160 SHARC processors?

Overlays are used when a processor does not have sufficient internal memory to hold all of the application's data and/or program code.

How is overlay code transferred from external memory to internal memory?

The code responsible for transferring the data/program code from external memory to internal memory at runtime is called an overlay manager.

What packing mode must be used with the actual ADSP-21160 device?

Use the following packing mode with the actual device: PACKING (12 B3 B4 B5 B6 B0 B11 B12 B1 B2 B0 B7 B8 B9 B10 B0).