I am currently developing an application for Windows CE on the TI OMAP processor, which is an ARM processor. I am trying to simply call a function in a C++ DLL file from C# and I always get a value of 0 back, no matter which data type I use. Is this most likely some kind of calling convention mismatch? I am compiling the DLL and the m...
I am looking for a fast, integer only algorithm to find the square root (integer part thereof) of an unsigned integer. The code must have excellent performance on ARM Thumb 2 processors. It could be assembly language or C code. Any hints welcome. ...
Does anyone know how to enable ARM FIQ? ...
Hello everyone, I'm tasked with choosing an open source web browser to run on a fairly low-end embedded Linux system, that is ARM based. I'd really appreciate some advice. I've been doing some research and there appear to be a few choices: Firefox/Mozilla - too huge to run on limited resources Konqueror/Embedded - the development appe...
Hi gusys, I knew there is a similar post: http://stackoverflow.com/questions/209603/steps-to-make-a-led-blink-from-a-c-c-program But now I am working on a arm-based development board, and it seems to have two serial ports that I could use it to make a LED on or off. Basically I think the flow is , make one pin in serial "1" or on and ...
The justification that I've seen for shall we say "Bastardizing" the Java bytecodes in Android was performance. (I suspect there is another reason.) However by changing the byte codes haven't they made hardware excelleration technologies such as Jazelle moot, and thus actually degraded the performance available for a Mobile Java platfo...
Hi I have a VxWorks application running on ARM uC. First let me summarize the application; Application consists of a 3rd party stack and a gateway application. We have implemented an operating system abstraction layer to support OS in-dependency. The underlying stack has its own memory management&control facility which holds memory ...
The question below was related to the 8051 family as it has only the serial ports. Now when i found out that the ARM processors have inbuilt ethernet facility i decided to mov on to the ARM's. So which would be the Most easiest one to start of and as iam aware of keil environment i would like to work on anARM which supports keil . Thnx...
I'm writing an embedded application on an ARM7 processor and I need some form of checksum for data that I'm sending over a serial link as well for data that I'm storing in the flash. I was wondering which of the two CRCs would be better suited for the purpose. The main trade-off are code speed versus robustness. Should I consider anoth...
The lackluster response here made me wonder this. I've been saddled with a device (Analog Devices 525x) that (from the data sheet, pg 16): disables the I2C interface during the internal [EEPROM] write cycle. That doesn't seem fair, as in "I'm getting off the couch now, so don't use it for a while because I let one rip in the s...
I was wondering if anyone had any hard numbers on ARM vs Thumb code performance on iPhone 3GS. Specifically for non-floating point (VFP or NEON) code - I'm aware of the issues with floating point performance in Thumb mode. Is there a point where the extra code size of bigger ARM instructions becomes a performance hazard? In other words,...
I was looking up some ARM assembly and i notice EOR/XOR and AND all set the C and O flag. How does that work? Are they always cleared? what conditions are they set? ...
I created a small module in assembler for ARM, to be linked together with my bare-metal embedded application. Sometimes when I'm rebuilding the application, I get a "Error[Lp002]: relocation failed: valued out of range or illegal". What is even more puzzling is that I'm getting the error after commenting out some code in a C module. T...
Is it advisable to directly start off with the datasheet and user manual of an ARM processor for a newbie or first get an idea about the ARM world and then go ahead? ...
How does Keil compare to GCC for ARM7 development? I'm in the process of choosing hw consultants for a medium size project and some use keil and some use gcc. I'd like to know the gotchas involved in going with either option... ...
I harbor a secret fantasy (oops, not so secret anymore) to build a simple computer from scratch. I'm looking for an easy-to-use microprocessor to start with. I know about the usual suspects such as the 6502, 68000, 8086, Z80, etc. But I'm wondering if something better is out there. Here's my wish list: Must have: Low clock rate (4-25 ...
Hi I am trying to include ARM assembly file **.asm in static lib which I am building using visual studio 2008. When I try to build solution which contains the library the visual studio crashes. The assembly file is generated from c fiile by selecting assembly-only listing option (FA). I add this to the library project and in its propert...
I have an application where a small embedded ARM9 device (running Linux) must gather information from sensors and then connect to a remote mySQL database and INSERT the data. I have Python 2.5 running on the ARM9 device fine. I have developed a prototype application in Python 2.5 running on x86 Windows and it connects with mySQL and INSE...
Let's say there is a simple test code typedef struct { int first; int second; int third; } type_t; #define ADDRESS 0x12345678 #define REGISTER ((type_t*)ADDRESS) const int data = (int)(®ISTER->second)*2; int main(void) { volatile int data_copy; data_copy = data; while(1) {}; } Which is compiled in Code...
I have two signed 16-bit values in a 32-bit word, and I need to shift them right (divide) on constant value (it can be from 1 to 6) and saturate to byte (0..0xFF). For example, 0x FFE1 00AA with shift=5 must become 0x 0000 0005; 0x 2345 1234 must become 0x 00FF 0091 I'm trying to saturate the values simultaneously, something like th...