This document introduces the design guidelines for the DDR2 interface supported by Analog Devices ADSP-2146x SHARC® processors family.
This document outlines hardware platform design guidelines for using the ADSP-2146x SHARC processors family with Double Data Rate 2 (DDR2) SDRAM memory devices. It covers signal grouping, naming conventions, and general PCB layout rules to ensure high-speed signal integrity.
Specific sections detail board-level termination recommendations, including series and parallel resistor placement strategies for the ADSP-21469 EZ-Board evaluation platform. The guide also addresses trace length matching, impedance requirements, and ground plane considerations for optimal DDR2 interface performance.
The ADSP-2146x supports a 16-bit DDR2 interface operating at a maximum frequency of half the core clock, with a maximum core speed of 450 MHz.
The PCB trace characteristic impedance must be approximately 50 ohms.
The ADSP-2146x SHARC processors have been designed to interface with DDR2 memories operating at a maximum speed of 533 Mbits/sec.