The Secrets of PC Memory: Part 4

jmke · 11th February 2008, 11:56

For better signal quality at higher speed grades, DDR3 adopts a so called “Fly-by” architecture for the commands, addresses and clock signals. This effectively reduced the number of stubs and signalling length from the DDR2 T-Branch architecture to a more elegant and straightforward design.

The Fly-by topology generally connects the DRAM chips on the memory module in a series, and at the end of the linear connection is a grounded termination point that absorbs residual signals, to prevent them from being reflected back along the bus.

We recently asked Aaron Boehm, an Application Engineer at Micron about how important the Fly-by topology is to DDR3. He said that the Fly-by design was “ very important in DDR3. Probably one of the biggest advantages of moving to the Fly-by topology is that we are able to achieve a much faster slew rate for the signal. This gives us a bigger data-eye, which is very important in DRAM.”

http://www.bit-tech.net/hardware/200...emory_part_4/1

11th February 2008, 11:56	#1
jmke Madshrimp Join Date: May 2002 Location: 7090/Belgium Posts: 79,022	The Secrets of PC Memory: Part 4 For better signal quality at higher speed grades, DDR3 adopts a so called “Fly-by” architecture for the commands, addresses and clock signals. This effectively reduced the number of stubs and signalling length from the DDR2 T-Branch architecture to a more elegant and straightforward design. The Fly-by topology generally connects the DRAM chips on the memory module in a series, and at the end of the linear connection is a grounded termination point that absorbs residual signals, to prevent them from being reflected back along the bus. We recently asked Aaron Boehm, an Application Engineer at Micron about how important the Fly-by topology is to DDR3. He said that the Fly-by design was “ very important in DDR3. Probably one of the biggest advantages of moving to the Fly-by topology is that we are able to achieve a much faster slew rate for the signal. This gives us a bigger data-eye, which is very important in DRAM.” http://www.bit-tech.net/hardware/200...emory_part_4/1 __________________

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
The Secrets of PC Memory: Part 3	jmke	WebNews	0	9th February 2008 14:49
The Secrets of Memory: Part 2	jmke	WebNews	0	17th December 2007 12:38
The Secrets of PC Memory	jmke	WebNews	0	16th November 2007 10:09
Interactive Memory Product ID guide to decode RAM part numbers	jmke	WebNews	0	16th October 2007 10:19
Basics of Flash Memory, Part 1: SD and MMC	Sidney	WebNews	0	11th March 2005 16:11
Guide to New Hardware Technologies Part I: Memory	Da_BoKa	WebNews	0	9th December 2004 16:19
FINAL Part of the Virtual Memory Optimization Guide Rev. 4.0	Da_BoKa	WebNews	0	17th November 2004 00:33
Virtual Memory Optimization Guide Part 4	jmke	WebNews	2	13th November 2004 14:50
Virtual Memory Optimization Guide Part 3	Sidney	WebNews	0	7th November 2004 19:12
Virtual Memory Optimization Guide Part 2	jmke	WebNews	0	3rd November 2004 15:49