Homemade config to SDRAM, Wait states and READ strategy. Need advice.

moller — Tue, 19 Jul 2016 14:15:20 GMT

Hello community!

I have a LPC4337 and I want to use the AS4C2M32SA 64MB SDRAM on this costum PCB. All connections are correct.

I tried to use some examples with various configurations but now I wanted to make my own setup of the EMC and SDRAM.

By using the UM10503 manual I have made a EMC and SDRAM config function. It will compile but I am sure that I have misunderstood a few concepts and I hope someone is willing to help me out a little bit:

On page 622 in the manual it states:

"2. When the SDRAM is in the set mode state, issue an SDRAM read from an address

specific to the selected mode and the SDRAM memory organization."

I have calculated the address to be 0x2803200 (MODE=0x32 and OFFSET to be 12). HOW do i use this infomation

and when is it to be used? (before or after setting the SDRAM timings?).

Secondly I need to delay by one "wait state" to acess those timing registers. Right now I have using empty for-loops

as delay but is this the prober way to do this?

I have attached my config to this post.

Kind regards

Original Attachment has been moved to: MyEMC.zip

Re: Homemade config to SDRAM, Wait states and READ strategy. Need advice.

bernhardfink — Wed, 20 Jul 2016 12:56:10 GMT

In general this topic is covered in various software implementations for the LPC1800/4300, also some app notes are available (mostly valid for LPC1800/4300 as well):

http://cache.nxp.com/documents/application_note/AN10935.pdf?fsrch=1&sr=1&pageNum=1

For the software side I recommend to have a look into the following packages and into the attachment (relevant files only):

http://cache.nxp.com/files/microcontrollers/software/LPCWare/lpcopen_2_12_keil_iar_hitex_eva_4350.zip

Regards,

NXP Support Team.

LPC MicrocontrollersのトピックHomemade config to SDRAM, Wait states and READ strategy. Need advice.

Homemade config to SDRAM, Wait states and READ strategy. Need advice.

Re: Homemade config to SDRAM, Wait states and READ strategy. Need advice.