is an ARM 32bit RISC processor core for microcontrollers

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Jitter in UART start-bit

Experimental setup: STM32F103RB microcontroller, Keil uVision 4.72, USART2 on PA.2, PA.3. Experiment: initialize USART for 9600 baud/s, initialize PORTA, initialize SysTick (for delays, interrupt ...
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1answer
58 views

STM32F103 GPIO not working

I am programming for LPC microcontrollers (mostly LPC1769), for the past few months with success. I decided though to give STM32 series a try. I just received a no-name board using an STM32F103C8 MCU ...
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1answer
40 views

STM32 USB Library - transmit fails with specific data lengths?

I am implementing USB communications on a STM32F107, using ST's USB Library v2.1.0. It communicates as a CDC class Virtual COM Port ("VCP"). I'm using the embedded Full Speed PHY. I've started with ...
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1answer
30 views

Flash memory read and write

I'm always disabling interrupts while writing to some sectors on Flash, but does Flash memory requires disabled interrupts even when you just want to read from it? Why yes and why not? Thanks for the ...
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12 views

IAP Flash LPC1788

Can this line cause a problem when reading from Flash, because of casting to BYTE pointer instead of DWORD? What will happen, and what data will be read? pointer_podatak = (BYTE*) IAP_BASE; ...
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1answer
35 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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1answer
89 views

Sram in the ARM cortex m3

I load a project into the chip STM32f103ZC whose internal sram is 48kBytes , there are also 2MBytes external sram on the board. But when I download and debug the project,the map file tells that ...
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22 views

CC2538 interrupt pin stopped working

I am using CC2538 with a motion sensor. Whenever the motion sensor detects any motion, it sends an interrupt to CC2538 to send it to another CC2538. I have used RF1.5 as an interrupt pin and has ...
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1answer
43 views

Calculating processor utilisation

I'm using a Cortex M3 processor on an LPC1769 board. For this particular situation, all processes occur within interrupts. Therefore, within the main "loop" there isn't actually anything to be ...
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3answers
46 views

Will XORing the FIO0PIN register on an LPC175x6x give unexpected results?

Is this code guaranteed to only effect pin 22? int* FIO0PIN = (int*)0x2009C014; *FIO0PIN ^= (1<<22); At first it seems like a dumb question but I remember ...
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1answer
61 views

How to use level-triggered interrupts with STM32F1xx?

I'm getting conflicting info on whether I can use level-triggered (as opposed to edge-triggered) interrupts with the STM32F1xx microcontroller. In ST's CMSIS-compliant Standard Peripheral Libraries, ...
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60 views

Strange behaviour using PWM on CortexM3

I have a board with the ATSAM3S2BA-AU, which is a Cortex M3 uC. I need to use 2 PWM channel , here how I've done it : ...
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1answer
161 views

Trouble holding MCLR line low for PIC ICSP, ICD3 works, hardware defect?

I have an ARM Cortex-M3 that talks to a dsPic33F. I am attempting to do ICSP programming of the attached PIC. I have an analyzer and can see that I cannot control the MCLR line the same way the ICD3 ...
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1answer
68 views

Will the ADC work with resistive inputs in LPC1796

I'm working with LPC1796 and I have to do data acquisition for my project somebody told me that LPC1796 microcontroller won't work with resistive inputs. What is a resistive input? Is there any way ...
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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
945 views

STM32F103, Having trouble nesting interrupts

I'm trying to interrupt into a USART handler from inside an RTC_Alarm handler, but it doesn't work. I have set the NVIC: ...
2
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1answer
90 views

Basic idea of color look up table

I'm driving an ILI9230 LCD 320*240 16bit interface, with a framebuffer of 250*200 and I want to drive it as 4bit. so I built a loook up color table like that: ...
2
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1answer
253 views

STM32F10x SPI - No Clock

I'm trying to get basic SPI operation working on an STM32F107VC chip using the WaveShare Port107 development board. I'm trying to initialise SPI1 which resides on PA4-PA7. I'm attempting a simple ...
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1answer
125 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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0answers
109 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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0answers
136 views

Choosing Cortex M3 for beginners [closed]

I looked at this thread already - "How to choose an ARM Cortex M3 microcontroller" However, my question is a bit a different. I want to focus on more of a learner/beginner's perspective. As the ...
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1answer
271 views

Porting Linux drivers specifically I2C

I am developing an I2C driver for an accelerometer. My objectives (actually it's the restriction I have as per the project guidelines given in my institute): use Linux flavour of operating systems ...
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1answer
221 views

Cortex M3 GPIO Interrupt won't trigger

I have set a pin on a Cortex M3 to act as an rising-edge triggered interrupt and it's not firing for some reason. What it should do is receive a 1Hz pulse, trigger an interrupt and start a 12.8Khz ...
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1answer
988 views

TCP/IP stack library for ST microcontroller

I'm looking for a free function library, that implements TCP/IP stack for STM32F103CBT7 (Cortex M3) microcontroller. The datasheet of this controller is following: ...
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3answers
574 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 ...
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3answers
643 views

How fast can ARM Cortex M0s/M3s bit bang?

I have not yet used ARM Cortex uCs, only AVRs Firstly, how fast can they: Stream 1024+ bits (serially, from bytes in RAM) out of a pin, with no pauses/jitter Stream 1024+ bytes (parallel, from RAM) ...
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314 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 : ...
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0answers
188 views

Atmel Studio JTAG Debugger Behaviour

The qeustion: I would like to know what is different about the way JTAG treats the "step over" and "step into" commands. Background: I am trying to set a GPNVM bit on a SAM3N (ARM Cortex M3) chip ...
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2answers
123 views

Task switching on Cortext-M3 crashes after IRQ

I've used an exokernel model for my ARM OS. When a task wants to read from a UART it calls a library function, which, if there's no data, makes a SVC call to block the task (which causes the kernel to ...
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1answer
511 views

Is it possible to control a 4 wire Bipolar stepper motor with a PWM signal?

I am trying to control a 4 wire bipolar stepper with a PWM signal being output from a VEX cortex controller. I am planning on using 4 bipolar NEMA 17 12v steppers to drive a small remote controlled ...
2
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2answers
650 views

The GCC Ride7 STM32 startup script does not jump into SystemInit function

We are a robotics association from ENSEIRB-MATMECA (Bordeaux, France). We are developping some boards and a template project for STM32 devices. One of our boards embed a STM32F103C4 microcontroller. ...
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1answer
309 views

If a controller has MPU, will it run Linux efficiently?

I have an EFM32 board having Cortex M3. This board is having an Memory Protection Unit. Will it be a good idea to port Linux on it? I am discouraged because of this answer: Linux on ARM Cortex-M3 ...
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75 views

Which will boot faster: FreeRTOS or MuCLINUX: need general guidelines?

Are there any general guidelines/thumb-rules to select OS? I have to port it on Cortex M3 based chip. Which OS should be selected: FreeRTOS or MuCLinux if I want the boot time minimum?
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3answers
3k views

Laying out a 10-pin JTAG/SWD connector on a final design

I'm designing a board with an ARM microcontroller on it (LPC1347FBD48) and I want to include a 10 pin jtag/swd connector, as is standard, for in-circuit debugging of my final design. Here is the ...
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3answers
867 views

Cortex M3 delay 1us

Im trying to achieve 1us delay to be able to drive 1-wire bus. My proc is working on 10Mhz PCLK so I tried to use timer function with overflow on 10th cycle. For some reason it gives me resolution of ...
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2answers
410 views

LPC1788 reading via SPI from ENC28J60

I have a problem with SPI communication with ENC28J60 chip. Basically I can't use SSP in SPI mode as it is, because ENC28J60 expects CS to be low for multiple bytes while SSP shifts it high after each ...
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3answers
6k views

Any ARM based microcontroller with integrated WiFi? [closed]

I am looking for a ARM based low cost SoC with an integrated WiFi, tried different search engines and still not been able to locate one. I would like to know if anyone knows of such device that has ...
0
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1answer
384 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
1k views

STM32 I2S Interupt Usage

I was trying out a sound experiment, starting off with sample code which sent data to the Discovery F4's audio codec using I2S. The sample code used polling in the main loop and sent data when the ...
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0answers
548 views

IAR EWARM project doesn't run with STM32 startup file

I'm attempting to test out some basic programs on an STM32L151RD (Cortex-M3) using IAR's Embedded Workbench. I'm using an ST-LINK/V2 programmer. I've downloaded the Standard Peripherals Library and ...
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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2answers
2k views

Faster IO on ARM Cortex-M3 (Sam3x8e) than PIO_SODR and PIO_CODR?

I have a very simple C program that toggles a pin on a Cortex-M3 board (SAM3X8E) with a 84MHz clock speed. I built this using Atmel Studio 6.1. ...
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1answer
312 views

Cortex M3 (ATSAM3N4B) Peripheral DMA read from SRAM ok, FLASH fails

I've stumbled across a peculiar problem with my PDC (Peripheral DMA Controller) where using the PDC to transfer a constant string from flash over UART 0 seems to produce an unexpected result. The ...
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2answers
126 views

Raw ip, ethernet response time on cortex-m3 based microcontroller [closed]

What's the minimal response time on cortex-m3(m4) based processor (like fujitsu MB9BD10S/T) to the raw ip or raw ethernet request? The request is as simple as possible to meet this conditions: ...
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1answer
8k views

Understanding Timers, Counters and Prescaler Registers on the STM32

So I'm trying to set up a very simple periodic interrupt on my STM32VL-Discovery board using the libopencm3 libraries on linux. I've looked at the documentation and I just want to verify with ...
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2answers
732 views

Nintendo Game Boy emulation using Cortex M3

I am planning to build a Nintendo Game Boy simulator using ARM Cortex M3 processor. I have no idea how to interface with the game cassette. Could anyone give some hints about it?
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2answers
181 views

Idea Hunt, FPGA + ARM Cortex-M3 [closed]

I aim to demonstrate the need for FPGAs as compared to MPUs like (e.g. ARM Cortex-M3 based from TI/ST) in doing processing intensive stuff. I am looking for some help in this regard. I want to show ...
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3answers
479 views

How do I know I'm not drawing too much current for my 3.3V supply?

Continuing my learning expedition, I've decided to use the LM3S5R36-IQR80-C3 ARM Cortex-M3 MPU, to try and learn to build my own little experiment PCB, almost like the Teensy 3.0. The idea is to learn ...
2
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3answers
1k views

Program only runs when debugging in GDB - using Open OCD and Olimex arm-usb-ocd-h jtag to program at91sam3su

I'm trying to make my Atmel at91sam3u cortex-m3 arm chip make an LED blink. I have a Olimex ARM-USB-OCD-H jtag programmer, and I'm using Open OCD running on OS X to program my chip. I'm using the ...
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3answers
383 views

Does lack of MMU make any difference for applications?

Generic Linux can't be run on Cortex M3 because Cortex M3 has no MMU. Okay, there're special versions of Linux that can run there. The problem is I don't quite get how this affects application ...