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. S\ufffdren_Rennecke <rennecke@...> 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. S\ufffdren_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\ufffdt 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 S\ufffdren --------------------------------- Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/lpc2100/ To unsubscribe from this group, send an email to: lpc2100-unsubscribe@yahoogroups.com Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. --------------------------------- Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online
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Re: AW: [lpc2100] performance problems
2004-02-12 by Bogdan Marinescu
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