Lpc2000

Hello, 

 

Why does not the -WE for LPC2294 go active low together when the chips select 2 (CS2) turn active low ?

The PINSEL2.bit8 = 1 so the -WE signal should be activated.

I have also verified that p3.27 (-WE) goes three state when PINSEL2.bit8 = 0.

If I set BCFG2_bit.WP = 1 (write protection) the Test() function runs into a prefetch exception. 

 

void LPC2294InitExternMemory(void)

{

  /*

  // Octal Uart chip select.

  BCFG2_bit.IDCY = 3;     // 16.66nsec * (3+1) = 65 nsec.

  BCFG2_bit.WST1 = 15;    // 15 * 16.66nsec = 249nsec wait states for the UART

  BCFG2_bit.WST2 = 15;    // 15 * 16.66nsec = 249nsec wait states for the UART

  BCFG2_bit.RBLE = 0;     // 8 Bit access BLS3:0 high during access.

  //BCFG2_bit.BUSERR = ;  // Status bit 

  //BCFG2_bit.WPERR = ;   // Status bit 

  BCFG2_bit.WP = 0;       // Write protect off(0).

  BCFG2_bit.BM = 0;       // Burst rom bank off(0).

  BCFG2_bit.MW = 0;       // 8 bit(00) 16 bit(01) 32 bit(10) reserved(11)

  //BCFG2_bit.AT = ;      // Always zero

  */

  BCFG2 = 0x000079E3;

/*

  PINSEL2 = BIT2|         // JTAG port.

            BIT4|         // Data[0,15]

            BIT8|         // Enable WE

            BIT11|        // Enable CS1

            BIT14|        // Enable CS2

            BIT23|        // Enable address line A0

            BIT24|        // Enable address line A1

            BIT26;        // Enable address line A2-A5.

            */

  PINSEL2 = 0x05804914;

}

 

BYTE testArray[10];

 

void Test(void)

{

  BYTE *ptr;

  int i; 

  ptr = (BYTE *) 0x82000000;

  i = 9;

  while(i--) {

    *ptr = i; 

    i++;

    i--;

    testArray[i] = *(ptr++);

  }

}

 

You have any idée what is wrong?

 

Sveinung



[Non-text portions of this message have been removed]

--- In lpc2000@yahoogroups.com, "Sveinung Waade" <sveinung@w...> 
wrote:
> Hello, 
> 
>  
> 
> Why does not the -WE for LPC2294 go active low together when the 
chips select 2 (CS2) turn active low ?
> 
> The PINSEL2.bit8 = 1 so the -WE signal should be activated.
> 
> I have also verified that p3.27 (-WE) goes three state when 
PINSEL2.bit8 = 0.
> 
> If I set BCFG2_bit.WP = 1 (write protection) the Test() function 
runs into a prefetch exception. 
> 
>  
> 
> void LPC2294InitExternMemory(void)
> 
> {
> 
>   /*
> 
>   // Octal Uart chip select.
> 
>   BCFG2_bit.IDCY = 3;     // 16.66nsec * (3+1) = 65 nsec.
> 
>   BCFG2_bit.WST1 = 15;    // 15 * 16.66nsec = 249nsec wait states 
for the UART
> 
>   BCFG2_bit.WST2 = 15;    // 15 * 16.66nsec = 249nsec wait states 
for the UART
> 
>   BCFG2_bit.RBLE = 0;     // 8 Bit access BLS3:0 high during access.
> 
>   //BCFG2_bit.BUSERR = ;  // Status bit 
> 
>   //BCFG2_bit.WPERR = ;   // Status bit 
> 
>   BCFG2_bit.WP = 0;       // Write protect off(0).
> 
>   BCFG2_bit.BM = 0;       // Burst rom bank off(0).
> 
>   BCFG2_bit.MW = 0;       // 8 bit(00) 16 bit(01) 32 bit(10) 
reserved(11)
> 
>   //BCFG2_bit.AT = ;      // Always zero
> 
>   */
> 
>   BCFG2 = 0x000079E3;
> 
> /*
> 
>   PINSEL2 = BIT2|         // JTAG port.
> 
>             BIT4|         // Data[0,15]
> 
>             BIT8|         // Enable WE
> 
>             BIT11|        // Enable CS1
> 
>             BIT14|        // Enable CS2
> 
>             BIT23|        // Enable address line A0
> 
>             BIT24|        // Enable address line A1
> 
>             BIT26;        // Enable address line A2-A5.
> 
>             */
> 
>   PINSEL2 = 0x05804914;
> 
> }
> 
>  
> 
> BYTE testArray[10];
> 
>  
> 
> void Test(void)
> 
> {
> 
>   BYTE *ptr;
> 
>   int i; 
> 
>   ptr = (BYTE *) 0x82000000;
> 
>   i = 9;
> 
>   while(i--) {
> 
>     *ptr = i; 
> 
>     i++;
> 
>     i--;
> 
>     testArray[i] = *(ptr++);
> 
>   }
> 
> }
> 
>  
> 
> You have any idée what is wrong?
> 
>  
> 
> Sveinung
> 
> 
> 
> [Non-text portions of this message have been removed]

Sveinung

I seem to remember that with an 8 bit bus the processor uses /BLS0 as 
it's write enable pin. I fell into the same trap!!!

regards

Doug