Lpc2000

Hi
Does anyone know if it is possible to run with internal FLASH and 
RAM, but also have an additional SRAM and 8-bit peripheral on the 
external bus?

From the data sheet it looks like it should be, but if I run from 
internal FLASH I don't get any bus activity if I try to access the 
external memory.

many thanks
Simon

Hi Simon,

>> Does anyone know if it is possible to run with internal FLASH and 
RAM, but also have an additional SRAM and 8-bit peripheral on the 
external bus? <<

I bl**dy well hope it does, otherwise I'm stuffed! <g>

>> >From the data sheet it looks like it should be, but if I run from 
internal FLASH I don't get any bus activity if I try to access the 
external memory. <<

I've only just got my board back, so haven't actually tried it yet, but one 
suggestion would be to check whether you've set up the registers (PINSEL0-2) 
to configure the relevant pins as address and data lines. 

The only other thing I can think is that you haven't setup the compiler to 
access *external* RAM for the relevant locations...

Cheers,

Rob

Yes it is possible.  The LPC-SBC2 at http://www.theARMPatch.com
operates in that manner.  It uses internal flash for program space,
internal RAM for stack space, external RAM for variables and buffers,
and accesses its ethernet controller and CompactFlash interface on the
external bus.

Regards
-Bill Knight
www.theARMPatch.com


On Tue, 12 Oct 2004 14:53:18 -0000, itsjustimpossible wrote:


Hi
Does anyone know if it is possible to run with internal FLASH and 
RAM, but also have an additional SRAM and 8-bit peripheral on the 
external bus?

From the data sheet it looks like it should be, but if I run from 
internal FLASH I don't get any bus activity if I try to access the 
external memory.

many thanks
Simon

--- In lpc2000@yahoogroups.com, "itsjustimpossible" <simonjh@b...> 
wrote:
> 
> Hi
> Does anyone know if it is possible to run with internal FLASH and 
> RAM, but also have an additional SRAM and 8-bit peripheral on the 
> external bus?
> 
> From the data sheet it looks like it should be, but if I run from 
> internal FLASH I don't get any bus activity if I try to access the 
> external memory.
> 
> many thanks
> Simon

You sure can. I'm currently running an external 8 bit lcd and 2*16 
bit sram chips. I also use both the internal flash and sram.

I'm using CS1,CS2 and CS3 for the external devices. Below is my setip 
code and it seems just to work!


	dummy = PINSEL2;
	// set extended memory D0-D16 CS,CS1,CS2,CS3 A0-A19
	dummy &= ~(0x00000020);
	dummy |= 0x00000010;
	
	// enable /WE,/CS1
	dummy |= 0x00000900;
		
	// enable /CS2,/CS3
	dummy |= 0x00014000;
	
	// enable A0,A1, A2-A19
	dummy |= 0x0d800000;
					
	PINSEL2 = dummy;	


	// set up the external sram on CS1
	dummy = BCFG1;	

	// 1 idle cycle
	dummy &= ~(0x0000000f);	
	
	// 3 wait states, 16 bit wide bus
	dummy &= ~(0x000003e0);	
	dummy |= 0x00000460;	

	// 3 wait states
	dummy &= ~(0x0000f800);	
	dummy |= 0x00001800;		
	
	// 16 bit bus
	dummy &= ~(0x30000000);	
	dummy |= 0x10000000;					
	BCFG1 = dummy;

	// set up the external non volatile sram on CS2
	dummy = BCFG2;	

	// 1 idle cycle
	dummy &= ~(0x0000000f);	
				
	// 3 wait states, 16 bit wide bus
	dummy &= ~(0x000003e0);	
	dummy |= 0x00000460;					
		
	
	// 3 wait states
	dummy &= ~(0x0000f800);	
	dummy |= 0x00001800;			

	// 16 bit bus
	dummy &= ~(0x30000000);	
	dummy |= 0x10000000;					
	BCFG2 = dummy;

	// set up the lcd on CS3
	dummy = BCFG3;	
	// maximum idle cycles
	dummy |= 0x0000000f;	
	// maximum wait cycles
	dummy |= 0x000003e0;	
	// maximum wait cycles
	dummy |= 0x0000f800;	
	// 8 bit bus
	dummy &= ~(0x30000000);		
	BCFG3 = dummy;

Thats great!
I had setup the EMC config, but had bypassed the PINSEL2 register 
when compiling for internal FLASH!

I have added another section to the start-up file to configure 
PINSEL2 and magically everything works as expected.

many thanks
Simon

--- In lpc2000@yahoogroups.com, "douglasbolton" <doug@c...> wrote:
> 
> --- In lpc2000@yahoogroups.com, "itsjustimpossible" <simonjh@b...> 
> wrote:
> > 
> > Hi
> > Does anyone know if it is possible to run with internal FLASH and 
> > RAM, but also have an additional SRAM and 8-bit peripheral on the 
> > external bus?
> > 
> > From the data sheet it looks like it should be, but if I run from 
> > internal FLASH I don't get any bus activity if I try to access 
the 
> > external memory.
> > 
> > many thanks
> > Simon
> 
> You sure can. I'm currently running an external 8 bit lcd and 2*16 
> bit sram chips. I also use both the internal flash and sram.
> 
> I'm using CS1,CS2 and CS3 for the external devices. Below is my 
setip 
> code and it seems just to work!