Lpc2000

OK You're right, I compiled in Arm Mode with optimize Level 3 and I
reach the same Baud rate. 


-----Ursprüngliche Nachricht-----
Von: Bogdan Marinescu 
Gesendet: Donnerstag, 12. Februar 2004 08:42
Betreff: Re: AW: [lpc2100] performance problems

    Thumb mode is perfect for speed optimization for chips with a 16-bit
internal and/or external memory bus. In this mode ARM instructions would
require two memory accesses and thus ARM mode would be quite slow.
However, this is not the case with the LPC, so I really can't see how
Thumb mode can help you speed un things in this case. Please someone
correct me if I'm missing something.

Sören_Rennecke <rennecke@corscience.de> wrote: 
Yes it was my aim.  I read it here:
http://www.nohau.com/appnotes/arm-thumb.pdf

Correct me if I misunderstood, but it seems that you're compiling in
thumb mode in order to obtain a speed gain. This is wrong. Thumb mode
will decrease the size of your application but will reduce its
performance. Run everything in ARM mode with full optimizations; if this
fails, write the ISR in assembler. If this still fails you'll have to
use a higher clock speed.

Sören_Rennecke <rennecke@...> wrote:
Hi,

What possibilities, are there to increase the performance. 
I need to process many instructions at my UART
interrupt-service-routine. So I get problems at higher Baud rates. 
I use the 14,745 MHz quartz, and don’t want to use the PLL (to save
current); pclk = cclk. 
I compiled the called functions in thumb mode, and optimized the output
with level 3. 
I reached a better performance, but are there other ways to get higher? 

Thanks Sören