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Using External 512kb x 8 bit SRAM with EMC of LPC2468

Philip Philipov

Hi!

I have a external SRAM ( CY7C1049CV33-15VXC ( 512K x 8) ) connected to:
LPC2468 ---- SRAM
P4.24 / OE = OE
P4.25 / WE = WE
P4.30 / CS0= CE
P4.[0-18] / A0-A18 = Address of SRAM
P3.[0-7] / D0-D7 = Data of SRAM

I tried to write a initialisation code, but i don't know how i can write and read into this SRAM.

I read from users manual that when use only CS0 the start memory address is 0x80000000.
I tried from "Options for Target" menu "Read/Write Memorry Areas" -> RAM1 Off-chip Start:0x80000000 and Size: 0xffffff..
And "No init" isn't checked, "default" is checked.
I tried to definite a char variable with the macro __at in the absacc.h (#include <absacc.h>).

char XRAM[524288] __at(0x80000000);

But don't works anything. My controller (LPC2468) blocks itself.

My SRAM is CY7C1049CV33-15VXC ( 512K x 8 bit).
How i can write and read from this SRAM and must i write a initialisation code?

I'm using Keil uVision3.

My initialisation code is here:

void SRAMInit()
{
        EMC_CTRL = 0x00000001;
        PCONP |= 0x00000800; // Turn On EMC PCLK

        // Configure EMC pins
        // Data Bus
  PINSEL6  = (1<<0)|(1<<2)|(1<<4)|(1<<6)|(1<<8)|(1<<10)|(1<<12)|(1<<14);//0x55555555; //D0-7

        // Address Bus
  // P4.[0-18] -> A[0-18] ADDRESS
  PINSEL8  = (1<<0)|(1<<2)|(1<<4)|(1<<6)|(1<<8)|(1<<10)|(1<<12)|(1<<14)|(1<<16)|(1<<18)|(1<<20)|(1<<22)|(1<<24)|(1<<26)|(1<<28)|(1<<30);//0x00555555;
  PINSEL9  = (1<<0)|(1<<2)|(1<<4);//0x00010000;

        // Control Bus
        // OE
        PINSEL9 &=(~((1UL<<16)|(1UL<<17)));
        PINSEL9 |=(1UL<<16);
        // WE
        PINSEL9 &=(~((1UL<<18)|(1UL<<19)));
        PINSEL9 |=(1UL<<18);
        // CS0
        PINSEL9 &=(~((1UL<<28)|(1UL<<29)));
        PINSEL9 |=(1UL<<28);

        EMC_STA_CFG0 = 0x80;
        EMC_STA_WAITWEN0 = 0x2;
        EMC_STA_WAITOEN0 = 0x2;
        EMC_STA_WAITRD0 = 0x1f;
        EMC_STA_WAITPAGE0 = 0x1f;
        EMC_STA_WAITWR0 = 0x1f;
        EMC_STA_WAITTURN0 = 0x0f;
}

How can i use this SRAM fastly?

Please help me!

Regards Philip

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