[En-Nut-Discussion] Re: [En-Nut-Announce] Version 3.4.2 Available

[Harald Kipp]

Lee,

At 11:09 17.03.2004 +0000, you wrote:

> >> 2. What is the current size of the ARM port?
> >
> > I did not succeed in compiling all modules, but
> > it looks like the ARM code is about 50-60% larger
> > than the AVR code.
>
>Is this 50-60% increase in program space?

Btw. did I ever answer the second question, that appeared?
Compilation was done for ARM mode, not Thumb, but including
Thumb support.

Yes, the figure was related to program space only.



>Has the data space requirement increased?

Sure, but I'm not able to give a number right now.
Expect an increase of about the same amount.

The thing is, that increasing RAM space will save
a lot of program space. Example

u_char i;
for(i = 0; i < 255; i++)

produces a lot of overhead for CPU architectures with more
than 8 bits. Using

int i;

Will add 3 bytes to RAM usage, but save some
code for masking out the upper bytes.



>I'm asking this, because I intend to use the ARM port on the Philips LPC21XX
>device. My intention is to run the program from FLASH, which can execute at
>full speed (zero wait states) upto 60MHz :-). Unfortunately this device has
>a 32K RAM limit.

If you take into account, that the httpd sample
still got about 20 kBytes of free RAM on the AVR
while waiting for a connection, that should be
no problem. In addition, it should be easy to
implement something like "optimize for RAM space".

Harald