Lpc2000

--- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
> --- In lpc2000@yahoogroups.com, "Randy Ott" <k5hj@q...> wrote:
> > I see now difference between the LPC2138 and 2148 in I/O speed.  
I 
> > have a piece of code that toggles an I/O pin to write to an 
> > external  FPGA.  The time to set then clear this pin is exactly 
the 
> > same with the 2148 as it was with the 2138.
> > 
> > This is a listing of the complied code:			
> 	
> > 	// Toggle WE pin
> >    \   00000048   4004A0E3           MOV         R0,#+0x40000000
> >    \   0000004C   000083E5           STR         R0,[R3, #+0]
> >     105              FPGA_WE_IOCLR = FPGA_WE_BIT;
> >    \   00000050   080083E5           STR         R0,[R3, #+0x8]
> > 
> > There are 2 STR instructions in a row to do the set/reset.  As I 
> > said, no difference in speed with the 2148.
> > 
> > Also, does anyone know where the 8k block of RAM for USB DMA is 
> > located in the memory map?  I would like to use this for general 
> > purpose storage.
> 
> Just guessing, I haven't seen a User Manual for LPC214x.  Since 
the 
> GPIOs are now accessible through the fast memory bus, they may 
well 
> be somewhere else in the memory map than the normal VPB 
peripherals.  
> And the speeds you are seeing could be because there exists a set 
> of "compatibility" GPIO registers at their old VPB addresses, with 
> their old VPB speeds.
> An LPC214x User Manual, philips_apps?
> 
> Karl Olsen

Good idea Karl.  I'm afraid I'll be old and gray before the user's 
manual is available.

I have a product that will go into production soon and it would be 
nice to design in the 2148.

Randy Ott