SDRAM questions

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by tvink on Fri Dec 19 08:26:17 MST 2014

Just read through AN11508, SDRAM Interface, and have a couple of questions.  I am using a single x16 SDRAM ( 4M x 16bit ).  My CPU is the LPC1837JET256.

I am looking at figure 6 in the app note. 

- Can I use any single DYCSx line that I want as long as the coresponding CKEx line is also used?

- For 16 bit I will be using DQM1 and DQM0 only.  Correct?

- What do I do with the feedback pins, CLK0 and CLK2?  Just a pad with no trace routed?

- Inside the CPU the signals are listed as EMC_CLK01 and EMC_CLK_23 but the pins CLK0 and CLK2 are used.  Do I really use pins CLK0 and CLK2 or
  should I be using pins EMC_CLK01 and EMC_CLK_23.  On the 256 ball package EMC_CLK2 and EMC_CLK_23 are on different balls.

- Lastly, is there a approved vendor listing of SDRAMs?