LPC MicrocontrollersのトピックRe: LPC4337 SDRAM Configuration

LPC4337 SDRAM Configuration

moller — Fri, 05 Aug 2016 08:56:31 GMT

I have my a config file to setup my SDRAM that can be see here: http://pastebin.com/YupajrwX

I have made a test-function to see if I can write and read data to SDRAM which can be seen here: http://pastebin.com/n1UMgbid

If I set Value = 0xAB00 0000 i get:
"Error at counter = 1"
"Error at address 0x2800 0000"
"Data at address 0x2800 0000 is: 0xABAB ABAB"

If i select Value = 0xBB00 0000 i get:
"Data at address 0x2800 0000 is: 0xBBBB BBBB

Howcome this "mirroring effect" takes place? Where am I failing and how can I fix this?

Re: LPC4337 SDRAM Configuration

soledad — Fri, 12 Aug 2016 23:16:36 GMT

Hello,

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://www.nxp.com/documents/application_note/AN11508.pdf

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

Have a great day,
Sol

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Re: LPC4337 SDRAM Configuration

moller — Mon, 15 Aug 2016 13:58:07 GMT

Hey Sol,

I used the EMC config and I can somewhat read/write from SDRAM.

I have made a test routine that writes from address 0x28000000. Data being written is 0x28000000+i.

When running this routine it stops at different itterations. Is this due to bad timing?

When setting the timing parameters I can't find following in my datasheet for the 64MB SDRAM (AS4C2M32SA-6TIN):

uint32_t ReadConfig;

/*!< Clock*/

int32_t tSREX;

/*!< Self Refresh Exit Time */

int32_t tAPR;

/*!< Last Data Out to Active Time */

If it is not timing based problems, what else could it be?

Kind regardsSigurd