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LPC1875 SDRAM Reading infinitely;CPU locked up

Question asked by sanjaymurthy on Feb 3, 2017

Hi,

 

I'm working on a custom board which uses LPC1857 cortex-M3 processor. The SDRAM AS4C16M16SA (4M word x 16-bit x 4-bank) connected to DYCS1. The SDRAM initliazation looks ok on the scope. Also SDRAM write seems to be ok. Below in the SDRAM/Controller configuration and intialization code attached. 

While reading a byte until address 0x30000000 to 0x30000003 everything seems ok and I think it is because of the buffer. After that porocessor locks up and goes for infinite read. I would appreciate if anybody could help with their ideas. 

testing method:

 

#define SDRAM_BASE_ADDR (0x30000000 | 0x3)

 

 

 

  //write
  add = (uint8_t *)(SDRAM_BASE_ADDR );
  for (i=0;i<66;i++)
 {
  *add = num1 ;
  //num1++;
  add++;
 
 }
  blink(led1);
  
      
  //read
   add = (uint8_t *)(SDRAM_BASE_ADDR );
  for (i=0;i<1i++)
  {
   val1[i] = *add;
   add++;
  }
  while (1) {blink(led2);}

 

-Using Keil MDK Pro and Jlink debug adapter

 

Thanks,

Sanjay

 

Original Attachment has been moved to: sdram-init.txt.zip

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