cortex-m3

Basically I'm having a hard time getting the execution time any lower than it is, as well as reducing the amount of clock cycles and memory size. Does anyone have any idea on how I can do this? The code works fine I just want to change it a bit. Wrote a working code, but don't want to mess up the code, but also don't know what changes to make. ; Calculation of a factorial value using a simple loop ; set up the exception addresses THUMB AREA RESET, CODE, READONLY EXPORT __Vectors EXPORT Reset_Handler __Vectors DCD 0x00180000 ; top of the stack DCD Reset_Handler ; reset vector - where the

I'd have some code that needs to be run as the result of a particular interrupt going off. I don't want to execute it in the context of the interrupt itself but I also don't want it to execute in thread mode. I would like to run it at a priority that's lower than the high level interrupt that precipitated its running but also a priority that higher than thread level (and some other interrupts as well). I think I need to use one of the other interrupt handlers. Which ones are the best to use and what the best way to invoke them? At the moment I'm planning on just using the interrupt handlers

I have an application that I am porting from the Keil IDE to build with the GNU toolchain due to license issues. I have successfully be able to set up, build, flash and run the application on the device. The application on the GNU side is for some reason is getting stuck in the weak linked IRQ handler for the WWDG which is an infinite loop. The application does not enable the WWDG, and it is disabled at reset by default. I have also verified that the configuration registers are at their default startup values. The only difference, other than compilers, are the linker and startup files. However

Given that, on the ARM Cortex M3, I can: atomically read a single bit atomically set a single bit atomically clear a single bit How can I combine these for a mutex style set of operations: try lock take lock release lock It seems that try_lock or take_lock would require two operations that would not be atomic. Do I need more control to accomplish this? Disable global interrupts would do it but it seems there should be a more surgical approach. Your rwl_TryLock() doesn't necessarily return a failure if the lock is already held when it's called (your compiler should be giving at least a warning

I am developing a control device with an embedded webserver. The webserver provides a control interface to any web browser that requests it (from Windows browsers, Mac browsers, iPhone android etc). The problem I am having is with a general way of generically knowing how to access the device. i.e. what address to type in the web browser. Fixed IPs are too techie for my users and could go wrong as my device could be plugged into many different Local networks. Using uPnp service discovery requires software to run on the client for some platforms and isn't as natural as just typing a web address.