This document provides technical notes on using Analog Devices' DSP components and development tools. It specifically discusses the features of ADSP-21065L, ADSP-21161N, and ADSP-TS101S from the floating-point family of DSPs, including their on-chip SDRAM interface for cost-effective designs.
This application note, titled 'The ABCs of SDRAM Memories', provides a technical overview of Synchronous Dynamic Random Access Memory (SDRAM) technology. It is designed to demonstrate the complexity of SDRAM, illustrating that it is more than just a memory component. The document covers basic internal DRAM circuits, timing specifications, and refresh issues.
An SDRAM cell stores data in a capacitor that holds a logical value based on its charge state.
Each storage cell consists of a very small capacitor ranging from about 20 to 40 femtofarads.
The capacitors gradually lose their charge and the device will lose its data.