Cortex-M is a series of ARM processor cores intended for microcontroller applications. ARM licenses the design to third-party chip manufacturers and does not manufacture devices themselves. They are promoted as being suitable for low-power / cost sensitive applications that still need high ...

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Difference between ARM A and M series processors?

When I'm asking this, I think on microcontrollers, whats the difference between A and M series of ARM processors. Many microcontrollers such as Beagle Bone now have A type of Cortex?
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35 views

SPI Flash Filesystem

I'm currently working on a portable product (microcontroller is the STM32F429) and store a lot of readings into a 128Mbit SPI flash (M25P128 from Micron). Essentially, I'm storing about 10 bytes or so ...
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14 views

is an unaligned STR in thumb2 atomic if it is supported by hardware?

This http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15414.html describes that some cores support unaligned stores but they may take longer if the store spans a 64 bit boundary. My ...
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1answer
41 views

Are unaligned LDRH/STRH supported on Cortex M3/M0?

Can all Cortex M0/M3 cores do this? LDRH r0, [0x8001] This would suggest yes but I don't see anything specific about Cortex-M cores.
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98 views

UART interrupt problem on LPC1788

I wrote a code ...
7
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4answers
1k views

My first STM32 code - please criticize me

I have just wrote my first code on STM32 - blinking LED. It combines a fragments from different sources; please criticize me so I can learn how to write proper code and don't learn stupid habits. ...
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1answer
50 views

Managing addresses of interrupt service routines and functions of the program in cortex M0

I am working with nordic nRF51422 uC with cortex M0 core and I have to store data in Non-Volatile Memory but to do that properly I need information where exactly code of the program is stored in ...
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1answer
81 views

Any Cortex-M3(LPC1768) compilers for Linux? [closed]

Are there any uVision alternatives for Ubuntu/Linux?, i know about LPCxpresso, but i just don't like it and its only for LPC MCUs. i tried Googling and it didn't help, I only saw results about ...
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109 views

CRC32 on SAM D20 (Cortex M0+)

I've been having a hard time debugging the DSU module on a SAM D20 (datasheet). I mean to utilize it to calculate CRC32 for a program I'm uploading through a custom bootloader (bootloader not mine). ...
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1answer
388 views

What is relation between ARM libraries

What is relation between CMSIS libs released by ARM.com, libraries provided by manufacture and GCC ARM libraries ? What is the exact purpose of each? Which of them Should I use?
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3answers
523 views

Which ARM MCU family is better for beginners? [closed]

Which ARM MCU family is better for beginners? I mean which family: Is straightforward and easier to learn Has more/better learning and development resources available Has bigger and better ...
4
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1answer
696 views

STM32F4 boot concepts and vector table relocation

There are some things I don't understand on the boot process of the STM32F4 microcontroller. My understanding is as follows: The ARM Cortex-M4 boots expects the stack pointer initialization value ...
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3answers
635 views

RTOS for Cortex M4 with 802.15.4/6LoWPAN stack

I'm evaluating operating systems to use in an Internet of Things Project and I don't know what's the best way to proceed. I'm using a TM4C123GH6PM MCU with 32k RAM and a CC2520 802.15.4 transceiver, ...
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0answers
272 views

STM32 ADC: Multiple channels with different sampling rates

I am trying to figure out how the STM32 multiple channels ADC conversion works (regular group). Lets say I want to convert on two channels, channel 1 and channel 2, on ADC1 and the sampling rates are ...
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2answers
438 views

Assembler coding for ARM (Cortex-M0 and M3): is it possible/practical?

Unfortunately there are no questions on Stack regarding ARM and assembler at all. My concern -- is time critical devices. Let's take for an example one of my AVR-based device (program compiled with ...
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3answers
258 views

Do I need OS for ARM Cortex-M0(3)?

I'm a developer of control devices for switch mode power supplies which need to generate a PWM signal(s) with a frequencies about 100 kHz, measure analog signals, communicate vie USART, make ...
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1answer
148 views

SD Card Access Library

I am accessing my SD card using SPI. But I've found this to be slow and I am also sad that when there is a faster protocol already supported by my SD card I am using a slower version. Is there a C ...
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2answers
48 views

Why doesn't the MCU's pin go high on time?

I have a STM32F103 and I downloaded this program to it(a simple blink program): ...
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2answers
152 views

Measuring power consumption of a design ranging uW to tenths of mW

I want to measure the power consumed by my design ranging from uW to tenths of mW. Power values I wish could be recorded digitally so that I can use them for analysis later. May be another form is ...
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1answer
129 views

Code Security of ARM Cortex M4 MCU

What are the main methods the code inside a certain ARM Cortex M4 MCU (TI LM4F120H5QR etc) can be extracted after deployment? Is it possible to completely stop a third party from stealing the code ...
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1answer
258 views

External MMU for cortex-M

The Cortex-M processors are getting faster and more powerful. The Cortex-M7 has just been announced. Yet these cannot run Linux (other than uCLinux) because the chips lack an MMU - Memory Management ...
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1answer
235 views

ARM Cores Benchmark

I am taking some deep interest lately in the ARM architecture and there are many flavors of ARM out there....ARM7, ARM9, ARM11, ARM Cortex-A, ARM Cortex-M and etc. Are there any benchmarks of all the ...
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2answers
136 views

ARM cancel execution of pre-empted interrupts

I can't seem to find an answer to this in google or the Definitive guide... Is it possible to from one interrupt, cancel the return to any pre-empted interrupts? For example, I have an ISR which is ...
2
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1answer
146 views

What's the concept of these three options for configuring the memory of STM32?

I have read the STM32F10x Reference manual but a section about "Reading the Flash memory" is not clear to me, yet. I mean this part(page 59): I have several question: What's the Latency? in fact ...
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82 views

Differences between ARM, Cortex-Mx, MCU Manufacturer, Dev Board?

I trying to find out ways to send HTTP requests from a development board (EK-TM4C1294XL) and trying to find libraries and code samples and what not (note: this is not my actual question). I want to ...
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0answers
124 views

Can the Hidden Markov Model be run on an ARM Cortex-M3 processor?

I'm working on an algorithm for a device that utilizes the Hidden Markov Model (HMM) to crunch data and make its predictions. Can the HMM be run on an ARM Cortex-M3 processor running at 32MHz? How ...
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1answer
80 views

The same flag for an interrupt

I think I'm mixed up a bit in NVIC of stm32 MCUs. I took a look in the SPI.h of the STM32F10x standard peripheral library. I don't know that why while there is ...
2
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4answers
517 views

minimal ARM (cortex m0) board

First: I'm not a professional. I just want to know what is possible and if i'm on the right track. Second: I want a little microcontroller which just measures (for example) the temperature and send ...
3
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2answers
181 views

Moving code from an ARM M0+ to an ARM M4, what changes?

Say I have a very simple program that functions perfectly fine on a ARM Cortex M0+ processor. How much will I need to change in order for it to work on an ARM Cortex M4 processor, assuming they are ...
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1answer
134 views

Recomendation for simple Cortex-M Flash Programmer [closed]

Looking for a recommendation for a simple, inexpensive, flash programmer for the Cortex-M - specifically the nRF51822. My project is ready to move into the short run prototype stage and I need to ...
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0answers
161 views

What is a Good Dev Board for Learning ARM for an Arduino User? [closed]

Lets start from my background: I am an Arduino veteran. I have played around with a lot of sensors and know a bit about hardware and software. I knew from the start that ARM platform has a lot of ...
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2answers
707 views

External Code Execution on ARM Cortex M

Is it possible to run code on the ARM Cortex M architecture from locations other than the onboard flash memory (such as another flash chip, SD card)? If so, how? If not, what microcontroller ...
8
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4answers
1k views

What are the differences between rand() function and RNG (Random number generator) peripheral?

I'm wonder for RNG (Random number generator) peripheral in STM32F4XXXX MCUs. look in this Reference Manual (page 748). On the other hand, we have the rand() function in stdlib library that do the same ...
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1answer
119 views

Writting Joystick drivers for ARM Cortex [closed]

I need to write a driver for Xbox360 joystick controller, using its module and everything. The idea isn't just take the code, I'm really interesting in the theory behind it. Does anyone have any ...
4
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3answers
589 views

Is there any difference between the assembly instructions of ARM MCUs from two different corporations?

I'm curious to know, are there any differences between the assembly instructions of ARM MCUs from two different corporation? For example between an Cortex-M3/4 of NXP and TI or ST or other ...
4
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3answers
2k views

STM32F4 - Floating point unit ( FPU )

I would like to know, what is the purpose of the special FPU unit, that is advertised with STM32F4 microcontrollers ? To quote this website : " The Cortex-M4 core features a Floating ...
3
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2answers
366 views

Can Tiva C run code from SRAM?

All I know is that although Cortex-M3/4 micros are Harvard architecture, they can run code from RAM, at least some implementations can (like STM32F4). Can Tiva C series microcontrollers execute from ...
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2answers
343 views

Force Cortex-M3/4 reset from assembly

I would like to force my STM32F4 to reset on fault, I tried to copy NVIC_SystemReset in assembly as : ...
8
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3answers
3k views

Endian problem on STM32

I'm using arm gcc (CooCox) to program an STM32F4discovery, and I've been wrestling w/ an endian problem I'm sampling with a 24 bit ADC via SPI. Since three bytes are coming in, MSB first I had the ...
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0answers
129 views

Good (modern) sources on ARM Cortex hardware design [closed]

I am looking for some good resources on getting started in embedded hardware design with the ARM Cortex series. I'm primarily interested in the Cortex-M, Cortex-A, and Cortex-A50 series of chips. ...
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0answers
539 views

ARM SWDIO only works when touching 3V and SWCLK with fingers

I made a new STM32F2 prototype board and SWDIO debugging only works when I connect the Vinputref and SWCLK with my fingers. It was working fine on previous boards: it's the same circuit but different ...
4
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1answer
657 views

Does the CPU of an ARM Cortex M halt during flash self-programming?

Most ARM Cortex M MCUs do not feature EEPROM memory. Instead, persistent data can be written to the same flash memory that also holds the program. What is the state of the CPU during this ...
13
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3answers
5k views

What's really the difference between the Cortex-M series and the Cortex-R series?

It's interesting! I searched for find a clear article, but I couldn't find a clear article for this. Also I found this link: ARM Cortex-R and this link: Cortex-R Series but they are not exactly clear. ...
3
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1answer
8k views

STM32 GPIO Configuration

I am trying to figure out some online resource to figure out how to configure the GPIO Registers on an STM32F4 Cortex M4 board. I only have examples for the Cortex M4 ...
2
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4answers
400 views

Is simple voice synthesis (just digits 0-9) possible with Cortex-M0+ with 4kB flash?

I'm working on a little side project with the LPC810 (Cortex M0+ 32 bit ARM MCU, 8 pin DIP package, 4kB flash, 1kB SRAM). I need a UI to convey to the user a temperature setting. I only have about 2 ...
0
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1answer
405 views

ARM Cortex M3 (ATSAM3N4B) IACCVIOL Hard Fault

The ATSAM3N4B is an ARM Cortex M3 microcontroller from Atmel. I wanted to ask if anyone can help clarify the IACCVIOL Hard Fault processing. What I want is the infringing instruction address which ...
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2answers
642 views

What is the data register address for GPIO pin 21 Cortex ARM M0?

I need to find data register address for GPIO pin 21 Cortex ARM M0? I feel this question can need some background. I am learning embedded MCU programming and most sources mention that I need to find ...
2
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1answer
414 views

Cortex-M0 interrupt nesting

Question 1: When one interrupt handler is executed, will it be interrupted if another interrupt with the same priority occurs? Question 2: When one interrupt handler is executed, will it be ...
4
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3answers
1k views

Sleep on Arm Cortex

I'm trying to put a cortex m4 processor (m3 with dsp extensions) to sleep for a little less than a second. I want to be able to tell it to sleep, then a second later, or when a button is pressed, pick ...
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1answer
653 views

Clocking scheme for LAN8720A - Cortex M4

This is regarding a design choice involving LAN8720, specific to clocking schemes. We are interfacing an ARM cortex M4 (with inbuilt MAC) to the 8720 PHY via RMII in the REFCLKO configuration. In the ...