• Get current active interrupt priority

    Hi everybody,

    We are working on a simple priority RTC (run to completion) framework for the Cortex M3/M4. Thanks to the NVIC/BASEPRI, we got most of this functionality for free but we want to extend it to user tasks.

    In our implementation we need to determine…

  • How many times same interrupt can be in pending state at a time? (In ARM CM-3)

    Could not find the answer to How many times same interrupt can be in pending state at a time? (In ARM CM-3) e.g. :

    We are processing one interrupt INT_RX, at the same time 3 more packets received. so I expect 3 times more this interrupt to appear sequentially…

  • 'Sort and Count' program using Cortex-M3 Assembly (or less preferably in C language)

    Construct the following null terminated string in code area (i. e. in ROM)

    str         DCB       “p1er3fec6tst1r2an5ge7rs8”.0

    Write an assembly program that will count and…

  • infinite Break Points

    Greetings,

                   sir/Madam the hardware break points use internal FPB comparators so that the address we update there are internally comare with program counter if value == program counter then automatically the core will be halted and ready to…

  • Instruction timings - arm cortex m3

    I am using the following 3 assembly sections to read a memory mapped i/o to multiple registers and to read same i/o and save it ram respectively , on an ARM Cortex M3. I want to know exactly how many CPU cycles this would take to complete. Or in other…

  • [C++11][Cortex-M] - distortos - object-oriented C++ RTOS for microcontrollers

    Hello!

    I finally decided to share some info about a project I've been doing for the past 8 months. Currently it can be considered "alpha" or maybe "early beta" stage, but - despite literal meaning of these terms - the things that are already done (and…

  • [CM3]assembly language trouble

    CORE: STM32F103ZET6

    Hi,Pros.

         Here Monkey comes agian

    I have met a problem with my code,see below:

    /* --------- code here --------- */
         .section .data
    _sp_usart:
         .word     _stack_usart
    _stack_usart:
         .space     0x100…
  • [CM3]UART always lose the last char

    Hi,there.

    I am using UART of my CM3 board,and there is something strange.

    I use minicom(a friendly serial communication program for linux) to Rx data came from CM3,and every thing goes well except that the last char is always lost. I have followed my program…

  • Addressing memory question for Cortex-M3

    First I apologize if I am in the wrong place to ask this but can't find info anywhere or I just don't know what question to ask regarding memory address for the Cortex-M3.

    I am very new to microcontrollers. I have an STM32F103VE and I downloaded…

  • How to get started with ARM Cortex-M3?

    Hi, I am eager to learn about ARM, I have a miniSTM32F1 board, and I have little bit knowledge of lpc2148? Please suggest me some tutorial,video,or links.

  • Im using an ARM Cortex-M3(LPC1768).I would like to know how many oscillator periods make up 1 instruction cycle for arm.Like for example,12 oscillator periods make up 1 instruction cycle for 8051.

    I would like to use the the number of oscillator periods for each instruction in delay calculations for instructions like NOP etc.

  • Compacting 4x 24 bit values into 3x 32 bits

    Hello,

    I have application running on an Cortex M3 MCU. The MCU runs a FIR filter which results in arrays of 32 bit values, but only the 24 least significant bits are used. Before storing this data to memory I want to compact four 24 bit words into three…

  • ARM Cortex-M3/M4 Toolchain and IDE

    Hi,

    I would like setting-up a ARM GCC Toolchain + IDE for developing for my Cortex-M3/M4 Processors (more types of cortex processors would be a plus). I downloaded GNU Tools for ARM Embedded Processors GCC ARM Embedded in Launchpad. What else do I need…

  • Cortex-M3 pipelining of consecutive LDR instructions to different memory regions?

    Hi all,

    recently I did some measurements concerning the SysTick-Timer and consumend clock cycles (because of performance reasons).

    I wrote a simple function in assembly, which gets called from a C file. Before and after the call i read the value of the…

  • How to configure a 10 inch TFT LCD in ARM Cortex-M3?

    good evening to every one..i am new to this website..i want to know how to use 10 inch TFT display and LVDS colour formet??? can anyone help me..? thanks advance

  • AMBA design kit

    I have a question about components of amba design kit.

    Is it correct design which contain arm cortex m3 with ahb-lite system bus, components bus matrix and ahb2apb bridge from amba design kit?

    Diagram with components connection in design is attached.

    AHB2APB.jpg
  • Cortex-M3 or -M4: Which is better?

    Hi,

    I need some clarification about which one is better either Cortex-M3 or -M4. Which one is present trending and which one having good future.

    Thanks in advance.

  • what changes to the source code of ARM Cortex-M3 can i make in order to shorten execution time?

    here are the 3 codes i need to change to shorten execution time.

    any help will be greatly appreciated.

  • Cortex-M3:Little endian

    Hi All,

    The cortex M3 in STM32F100xx devices stores in little endian format. Does this mean that even the memory locations which I see in KEIL window are in the little endian format? For eg: 0x20000AFF is actually 0x2000FFA0?

    Its getting a bit confusing…

  • Organization of startup from internal flash of Cortex M3

    Hi,

    i want to understand how the startup of a cortex M3 works. When i debug the startup i saw that from adress 0x0 a big area with DCW comes, like here:

    0x00000000 0268  DCW  0x0268
    0x00000002 2000  DCW  0x2000
    0x00000004 0505  DCW…
  • Loop unrolling on Cortex-M3 vs. Cortex-M0

    In the DSP lib files like arm_conv_f32, arm_fir_f32, the algorithm implementation in Cortex-M3/M4 and in Cortex-M0 is different. i.e., loop unrolling is used in M3/M4 and it is not used in M0.

    Pls tell me the reason behind it. Is there any advantage of…

  • Code Size – a comprehensive comparison of microMIPS32 and Thumb code size using many Megabytes of customer code

    In this blog I take a close look at the code size of ARM’s Thumb instruction set against the microMIPS32 instruction set, as used in the microAptiv processor family.  More specifically I look at recent claims that microMIPS32 has 17%-30% better code…

  • From “Which Cortex-M processor” to “Which C compiler”

    In my presentation at ARM TechCon 2013 last week "ARM Cortex-M for Beginners", someone asked a question of “Is there any advice for getting the best performance? Which C compiler to use?

    This is a very interesting question. One page of…

  • A tour of the Cortex-M3 Core

    In the previous post we looked at five features of Cortex-M processors. In this one, we will look at Cortex-M3 specifically.

    The central Cortex-M3 core is based on the Harvard architecture which is characterized by separate buses for instructions and…

  • Embedded World 2015 - Design of SoC for High Reliability Systems with Embedded Processors

    This is a paper published in Embedded World 2015, covering various areas about how chip designers can improve the reliability of a SoC (System-on-Chip) design. It also cover various functional safety related features in the Cortex-M7 processor, as well…