lpcware

EMC Interface on LPC4350

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by gregd on Tue Jun 19 09:50:53 MST 2012
We are designing a board based on the LPC4350 that uses 32 bit wide NOR FLASH (2 16 bit NOR FLASH EMC_CS0), 32 bit wide SRAM (4 16 bit SRAMS EMC_CS2 and EMC_CS3), and 32 bit SDRAM.  Can all of these parts be directly connected to the EMC interface on the LPC4350 with no issues? 

We do currently have 22 ohm series resistors on all of the EMC lines coming out of the LPC4350 to reduce EMI and ringing.  Are these necessary?

On the Hitex board, they are using output buffers for the address and control lines and bi-directional buffers for the data lines.  These buffers are connected to the SRAM and NOR flash parts only.  The SDRAM is connected directly to the LPC4350 with series resistors on the data lines only.  Are buffers recommended or required?  What is the purpose of them on this board?  Are the series resistors on the SDRAM data lines required for proper operation?

How many inputs can be connected to each address, data, or control line on the LPC4350?

Any recommendations/requirements would be very much appreciated. I can't find anything specific in the user manual, data sheet or app notes.

Thanks,
Greg Dunn

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