Re: [avr-libc-dev] AT43USB35x support!

[Keith Gudger]

I thought I had checked carefully that the FLASHEND was *word* address?
Are you sure that it's byte address max?

I guess that based on this discussion that we should limit the flash
memory size of the 320 to 32K words?

Keith

On Sun, 2 Mar 2003, Marek Michalkiewicz wrote:

> On Fri, Feb 28, 2003 at 03:36:39PM -0800, Keith Gudger wrote:
> > The 320 supports 16 address lines for *words* of external Program Memory.
> > The PC is 16 bits wide.  There is NO RAMPZ register.  SO, I guess what
> > this means is that one could have up to 64K of program code, but LPMs
> > would only be able to get to the bottom 32K?  I don't think any of us here
> > looked at this in detail - We've never put more than a 16K *byte* FLash on
> > the thing.  
> 
> OK, so for the 320 we can only support up to 64K bytes (32K*16) of
> program memory - GCC puts initialized data above program code, and
> the startup code for devices with >64K of program memory has to use
> RAMPZ and ELPM instruction in the loop that copies the data to RAM.
> 
> So, FLASHEND in io43u32x.h is defined as 0xffff (64K bytes) now.
> BTW, this is a byte address - I've fixed io43u35x.h to define
> FLASHEND as 0x5fff (24K bytes) instead of 0x2fff.
> 
> 64K bytes of program memory is still plenty anyway :)
> 
> Marek
> 
>