I have initialized the above controller in C++ in Keil 5uV. After the initialization, I want to jump to or enter a timing critical assembly language algorithm under the int main(void) statement. What is the preferred method to accomplish this?
MJ
I have initialized the above controller in C++ in Keil 5uV. After the initialization, I want to jump to or enter a timing critical assembly language algorithm under the int main(void) statement. What is the preferred method to accomplish this?
MJ
Hello,
I am wondering why CMSIS library have arm_bitreversal2.asm file written in assembly code however it could be written in c as others are written. In description of file it says it written to gain for maximum speed of fft but when I use real…
I have only used assembler when working with MCU's. I can follow a C program but have not used it in any commercial product. Can anyone suggest a development platform to start off learning the ARM and C? I would probably work on a Cortex M4F as a start…
Hi.
I wonder how to calculate absolute value of a 32-bit signed integer in C as fast as possible. I saw that there is a FPU instruction VABS.F32, which do that in one cycle (above the floats). I thought, if it is possible to use it also with integers …
Hello again.
As I am very interested in learning ARM architecture, I would have few questions regarding assembly programming. Questions refer primarily to programming Cortex-M processors, because they are the only one which I am using (at least for now…
Hi.
I would like to use bit-banding feature in SRAM, but don't know exactly how to implement it with C. I already use bit-banding in peripheral region with this kind of macro:
#define BITBAND_PERI_REF 0x40000000…
hi
I'm using the soft-core Cortex-M0,keil uvision 5,vivado 14.4
I am trying to implement a filter on my Cortex m-0 based FPGA
the main idea of this project is to create an accelerator from my C code to reduce the execution time ..and since my accelerator…
hello, I am in a research project and need the assembler guide with opcodes of armv7 processor.
I'm really looking manuals byte code assembler, not C language or C ++.
I need the hex values of each instruction, and the details of each mnemonic.
I am…
Hi,
I think I am just getting confused with this even if (or because of) I read the book and manuals again and again.
At exception entry, the processor saves R0-R3, R12, LR, PC and PSR on the stack. Saving PC means that the address of the instruction to…
I want to communicate NXP LPC2378 (ARM7 core) to some other devices via SPI (Serial Peripheral Interface) protocol.
So how to write a C code to communicate a particular device as a Slave with Master (ARM7 controller)?
Hi,
I have two M0 projects. The first project has only one assembly file startup.s. The second project has one assembly file and one C file. When I checked the memory map file of the second project (shown below), there are some extra object codes included…
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…
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…
Dear Mrs. /Mr.
We are a company that manufactures traffic light systems. Our RnD department is in the designing process of a traffic light controller (TLC). The basic operational bloc diagram of the system is shown on the following figure:
As you can…
I have been given the task of selecting a suitable processor for a project in which we will have a dedicated processor.
The project will involve configuring HW and inverting matrices in C. We will use the Cholesky algorithm in double precision. We don…
Hello all!
So I'm working on a development with a Cortex M4 and there is something i don't understand, I was hoping someone could help clarify this:
This is the code I' using
(Assume R3 content is 1, R6 R8 the address needed to set PIN1, and…
Hello to all,
I would like to measure the current variation due to Functional Unit activation and deactivation. Can anyone help me out with the assembly program or the code through which I can measure this? I am using LPCXpresso 54114 board(ARM Cortex…
Hello,
I need help with heap initialization using scatter file and C++ startup.
MCU is STM32F407VGT6 (Cortex-M4).
Compiler is ARM Compiler 6.7, C++14.
The problem is that all variables which I create dinamically on the heap have wrong addresses. My HEAP…
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…
Hi everyone,
I wonder if there is a documentation that explain how to program efficiently on arm cortex-m and arm cortex-r platform?
I found "arm system developer's guide", but i worried it was too "old-fashion" because it only contained upto armv6..…
Hi,
I am developing a fixed-point MP3 & ACELP decoder on an Arduino Due. I realize that bit-banding makes a RMW sequence atomic but I notice fields in the Due hardware are multi-bit fields. Is there an atomic way to alter multiple bits? I realize that…
I have a very simple CortexM3 based virtual platform example as below

The amba_pv_m2 is connected to a memory in the top. The BusDecoder master port address range is 0x0-0x3FFFFFFF
I have the following C program
#include <stdio.h>
int main(int…
Background
I'm working part-time on a Cortex M0+ based SoC converting a very processor-intensive section of C++ code (inner-loop executed 10s of 1000s of times a second & compiles to over 400 instructions using GNU O3) and after almost 3 months of work…
Hello,
We bought ARM CM0+ deliverables from ARM. I want to design an SoC which has to get data from an another system .The aim of the SoC is to process an array of 4096 samples received from the external world.For the data interfacing, we are using GPIO…