Questions tagged [arm]

32-bit microcontroller IP. The ARM company which designs the ARM cores doesn't make controllers itself, but licences the IP to other manufacturers. ARM is the leading 32-bit controller and is available from tens of suppliers.

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1answer
257 views

Is there a way to check if semihosting is enabled at runtime

The ARM Cortex cores has a built-in feature called semihosting which is a way to interact with the attached debugger, for example to do printf() debugging without using a peripheral unit. However, ...
2
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1answer
593 views

Interfacing SIM900A GSM Modem with TM4C123G TI microcontroller

I was hoping you guys could help me on connecting SIM900A GSM Modem with this TM4C123 micro controller. I connected the RS232 ports of TX, RX, GND and power ports to GND and +12V. should I connect ...
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2answers
896 views

STM32 software IDE [closed]

After a two year experience of ATMEL's SAM mcu I decided to move on STM32 microcontrollers. I choosed to begin with STM32F410RB. After a lot search on the internet I found two free IDE, Atollic ...
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2answers
409 views

Difference between MIPS and ARM datapaths [closed]

I have just learnt simplified five stage pipelined MIPS architecture in the class. I am reading other Instruction Set Architectures (ARM currently) and found some differences between ARM and MIPS. ...
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2answers
593 views

Reasons for multiple I2C modules in ARM-based MCUs

I was looking in the NXP product selection guide for ARM Microcontrollers. There are multiple I2C modules in most of the ARM MCUs. Since I2C is a multi-master multi-slave protocol, is there any clear ...
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1answer
772 views

What operating system manages resources in ARM cortex M4 based development board? [closed]

Is there any operating system written in board which manages its resources. My development board is STM32F407
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1answer
2k views

How to read several ADCs interfaces every n seconds per channel in STM32 MCU?

I'm using the ADC channels (12-bit resolution) of a STM32F0 microcontroller to read voltage values in three different points of a board. What I want to do is to read the values every 2 seconds (I have ...
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1answer
1k views

8-pin ARM JTAG interface header

An embedded device based on ARM926EJ-S revision 5 (ARMv5TEJ) chip. The PCB have 8-pin test points for connecting JTAG debug interface (2.54mm pitch). I tried to find specification for this type of ARM ...
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3answers
817 views

Driving Nokia TFT LCD with STM32

How do I increase the refresh rate of a Nokia LCD that I'm driving using the STM32F103 microcontroller? The LCD is 132*162 and takes a 9-bit instruction/DATA with RGB for each pixel in 565 format. ...
3
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1answer
395 views

Timer problem on STM32F7 - erratic behavior

First off I'm a complete n00b and just getting started with STM32. I'm encountering some weird behavior while setting up TIM1 and also using external interrupt EXTI3. I'm attempting to measure a low ...
11
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4answers
2k views

Getting fast performance from a STM32 MCU

I am working with the STM32F303VC discovery kit and I am slightly puzzled by its performance. To get acquainted with the system, I've written a very simple program simply to test out the bit-banging ...
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2answers
2k views

Are there 8 bit ARM processors?

Is there anything below 32-bits for an ARM processor? I was wondering if there is or ever was an 8-bit ARM processor. I've searched but not seen any and so it seems that ARM processors are either 32 ...
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0answers
203 views

ARM/Cortex-M comparison data source: Can someone give me a little lay of the land? [closed]

So there are soo many manufacturers making ARM and ARM Cortex-Mx chips and a few of them have I²S and I even saw one with S/PDIF. This wikipedia article gives me some lay of the land, but I need some ...
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2answers
2k views

Do CMSIS libraries also handle GPIO registers?

I'm currently exploring embedded programming with ARM processors. My embedded systems class has us programming on an Atmel SAMD20 (Cortex M0+). Our lab manual explains in detail how to utilize an ...
0
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1answer
484 views

What is the least amount of time that I can measure using STM32F1x Timers?

I am working with STM32F107 on a custom board, the board has 12MHz crystal. I want to measure 1 micro second precisely, but I am unable to do so. I have used STM32CubeMX to set the core clock at 72MHz ...
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2answers
4k views

STM32F103 ARM - Modifying Clock At Runtime - FLASH Latency

I am having b it of confusion regarding changing the clock tree of an STM32F103 Cortex M3 at runtime and I am hoping someone can help me with it. I am using a development board which has a 8Mhz HSE ...
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2answers
652 views

Periodic waking up from deep sleep

what are the main used ways of how to handle deep sleep of some microcontroller (atmega or a cortex m0/m0+) with waking up periodically? Right now, I'm building a Sigfox GPS tracker that should send ...
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2answers
1k views

Arm mode and Thumb mode makes the PC's bit 0

The ARM and Thumb modes are word-aligned and halfword-aligned. I understand this means that if it's in ARM mode, the start of addresses must be divisible by 32, and if it's in Thumb mode it has to be ...
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1answer
326 views

ARM architecture question [closed]

What is the role of marked area? Where is the address going? Also shouldn't there be an arrow from instruction decoder leading somewhere? I know basics of comp arch and know am aware of program ...
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0answers
132 views

SAM3X8E unresponsive

I have an Atmel SAM3X8E microcontroller on a board. According to the datasheet, it should provide a '>' prompt on the serial UART when it's powered on, to allow you to download code to it. Mine ...
2
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1answer
4k views

What is the difference between SPI,SCI and SDI?

Hi I'm trying to interface an audio codec chip VS1053B with my STM32L476 Microcontroller. But in the microcontroler there is SPI interface and in the VS1053B chip it is SCI interface with few extra ...
2
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1answer
880 views

STM32 - AHB Prescaler disabling Systick

I'm writing bare metal firmware for an STM32F070. When I set the AHB Prescaler (AHBCLKDivider) to a value greater than 1, the ...
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1answer
612 views

Undefined exception in ARM processor

Undefined exception in ARM processors is described as being taken when the processor encounters an instruction that is undefined or not supported by implementation. I am not able to understand that ...
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2answers
270 views

I2C Connection Mbed

I2C Comms I'm trying to connect an I2C 16x2 display (PCF8574T) to a nucleo-L476RG Connections Code i'm trying to run Output of printf RUN 0x0 ACK 0x1 ACK 0x2 ACK 0x3 ACK 0x4 ACK 0x5 ACK 0x6 ACK ...
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1answer
203 views

Do I need extra components for SAI with PCM?

I'm in the very early stages of designing a low cost audio device. I will be using PCM (probably 16-bit 44.1khz) audio. I haven't settled on a microcontroller yet, but the stm32f74 arm cortex m7 looks ...
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1answer
110 views

Countdown Timer on Switch Input ARM 7

I have been trying to create a countdown timer using ARM7 micro-controller, once an switch input has been detected. So far I managed to create a delay function of 1 minute, and detect a switch input. ...
2
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1answer
508 views

what is the purpose of __weak reference used on Keil MDK ARM?

Got a little messy with a function defined in two files and one with a __weak symbol. I called the below function to load the settings of UART1 in STM32L476RG from my main file ...
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0answers
501 views

J-Link device selection error in Keil

I try to load a program into STM32L011K4 using J-Link. The mistakes I get and the steps I follow are as follows: PROBLEM-1. J-link could not find STM32L011K4 My Steps: Click options for Target → ...
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3answers
555 views

Detecting Switch input in ARM 7 and multiplexing two seven segment displays

I am trying to multiplex two seven segment displays, once a switch input is detected. If a switch is pressed then the seven segment displays should show 1 If ...
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2answers
559 views

Interfacing Switch Input with Seven Segment Display using ARM 7

I am trying to detect a switch input so that, if the switch is pressed, a number is incremented on the seven segment display. For example if the seven segment display shows ...
4
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2answers
960 views

Atmel SAM E70 (ATSAME70Q21, Cortex-M7) battery backup

I'm building a USB-powered demo board with the Atmel SAM E70 controller, and a single hurdle I'm facing is the battery-powered operation. I intend to use a simple 3V coin cell battery as a backup ...
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2answers
295 views

STM32 timing critical ADC outline code

I intend to use an STM32F401RE (on a nucleo board) to capture some time based data. I am new to ARM and have an 8bit uC (AVR) background. I have a toolchain set up (using gcc as part of AC6 SW4STM32) ...
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2answers
255 views

Multiplexing 2-Seven Segment Displays using ARM 7

I am currently trying to control two seven segment displays from the same 7 pins (P0.0 - P0.6) of an ARM 7 micro-controller. I am first testing this on Proteus simulation software. I am following ...
0
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1answer
36 views

Need help for a trouble with Keil C window

I tried to program STM32 with Keil C but when I try to "Set Path" to the library, there is a problem like this: As you can see, the "Option for Target" window doesn't show all everything, there is ...
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1answer
1k views

Confusion about ADR in ARM (assembly code)

I'm confused on what's happening with ADR R14,cnt1. Is cnt1 signifying the end of the program? And if so how will ...
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0answers
131 views

Is it legal to design an open source AHB master?

Is it legal for open source cores to be compatible with the AMBA specification?
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0answers
221 views

How can I use an ARM chip to read & write 4164 DRAM?

I have an idea I'd like to pursue and partly because of their speed and partly because I'd like to begin ARM development I think a Cortex based board might be a good fit. I'm quite a proficient ...
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2answers
504 views

Using a 3.3V MCU (Arm) to control reset pin of a 5V MCU (AVR) without a level shifter [duplicate]

On my PCB I'm trying to avoid a level shifter chip. So is it possible to connect my ARM CPU's GPIO pin (which runs at 3.3V) to the reset pin of the AVR chip? I was thinking of setting the ARM GPIO ...
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1answer
425 views

What ISA is used by Cortex-M/R/A and what compilers are available? [closed]

What ISA is used by Cortex-M/R/A? What is the difference between arm-none-eabi and arm-elf-gcc? Are there any other compilers for ARM devices worth mentioning?
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1answer
1k views

How to set by software interrupt of USART in NVIC? - in fact emulate it

After putting data into STM32 USART register DR, data is being transfered and interrupt occurs(TXE,TXC). NVIC jumps into my IrqHandler code. How to set this same interrupt by software(and run ...
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0answers
251 views

What do ARM revisions mean? e.g. r2p1

Questions What do the "revisions" mean in the processor documentation at the ARM Information Center? Do they refer to silicon processor core design revisions, documentation revisions, or something ...
2
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3answers
623 views

Unable to program ATSAML21 PCB via SWD - Problem with connection?

Well, I'm officially stumped (and so are several other engineers)... I have a custom PCB running an Atmel ATSAML21E18B microcontroller, which I'm trying to program through an Atmel ICE debugger / ...
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5answers
7k views

where are constant variables stored in microcontroller?

As per the memory layout of C program ,constant variables are stored in the Initialized data segment of the RAM. But as per some of the Microcontroller memory layout ,const variables are stored in ...
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1answer
964 views

STM32F103 - NVIC Confusion

While reading the RM0008 reference manual I got confused about how to use the NVIC to configure interrupts. The manual basically redirects the reader to the PM0056 programming manual which, in my ...
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1answer
234 views

Atmel SAMC21 microcontroller unwanted resets

I am using an ATMEL SAMC21 MCU on an ebike project. The MCU is involuntarily resetting every 30s to 1min. This causes a problem as it's controlling the bike in real time, giving noticeable gaps in ...
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2answers
370 views

Arm Cortex-M Programming [closed]

Personally, I have experience on 8-bit and 16-bit architectures (such as Atmel or Microchip) and now I would like to continue with 32-bit ARM Cortex-M family. I wanted to learn the internals of Cortex-...
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1answer
770 views

How to program an ARM microcontroller?

Is there a way to program the ARM microcontroller without solder it to a dev board? I mean, if I want to develop a product based in the ARM architecture I suppose that I have to use one ...
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1answer
92 views

Need help tracking down the source of a delay between timer interrupts on SAM MCU

I have a project that outputs a series of values to DACs with a precise timing interval. The problem is that sometimes there is a delay longer than expected between the system timer interrupt in which ...
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3answers
4k views

Understanding difference between Interrupt Address and interrupt vector address

In my undergrads, I was taught 8051 and in interrupts my professor had said that on interrupt SP points to the address that is hardcoded and Program goes to excute those instructions. But in between ...
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1answer
730 views

Timers in TM4C123G not working

I wanted to use timers in TM4C123GH6PM (in TIVA C series TM4C123G Launchpad evaluation kit). So I decided to use GPTM TimerA0 in periodic timer mode. I defined the address of the registers of GPTM and ...