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Questions tagged [cortex-m4]

embbedded processor by ARM belonging to the Cortex-M family.

2
votes
1answer
36 views

Can I leave SWO/TDO and TDI of J-Link floating?

I'm designing a board with cortex-m4f having only SWDIO and SWCLK. I'm drawing schematics for J-Link's 9-pin JTAG/SWD connector, and I wonder if I can leave the SWO/TDO and TDI pins floating. J-Link'...
1
vote
1answer
49 views

How does ARM CMSIS functions access Core registers in unprivileged mode?

As per my understanding the ARM M4 core registers such as NVIC registers can be accessed only when the software is in privileged mode, that means it should be running in handler mode if I am correct. ...
1
vote
1answer
47 views

SAM Timer counter / atmel ASF

I'm trying to implement function call after having timeroverflow or comparison of counter registers. Chip: SAM4E ...
0
votes
0answers
60 views

STM32F4 CubeMX SysTick timer rate

I am using CubeMX to generate initialization code for STM32F407 MCU. I wonder where can i see the SysTick timer rate in CubeMX or its generated code? I am using 8 MHz external crystal and set SYSCLK ...
0
votes
0answers
97 views

Bus fault when accessing mcu internal peripheral

I am struggling with a bus fault error on my samg55 µC based on arm cortex m4 architecture. The issue occurs sporadically and is not 100% reproductible. Let me give some details. Application code ...
0
votes
0answers
28 views

Reading GPIO configuration (Cortex M4 ATSAME54)

I'm writing some diagnostics for a Cortex-M4 -- in this case an ATSAME54. I'd like to be able to read the configuration of individual GPIO pins, namely: bool level enum gpio_direction direction [IN, ...
2
votes
1answer
53 views

STM32F7 trimming step frequency

In the past I calibrated the frequency of the High Speed Internal oscillator (HSI) in an STM32F0 device adjusting the value of the register RCC_CR, field HSITRIM. In the ref. manual it says that the ...
0
votes
1answer
75 views

What is the difference between system clock and peripheral clock in case of arm Cortex M4 architecture? [closed]

System clock/core clock is the clock that drives the CPU. I understand that different internal peripherals use the oscillators. How do both differ from each other?
0
votes
3answers
75 views

STM32F4 executable stack?

Is the stack executable on the STM32F4 MCU? I want to do this: ...
0
votes
1answer
165 views

Range of the write protection registers on STM32 (WRP1AR etc)

I want to enable write protection on the flash pages occupied by the bootloader on an STM32L4 chip. I understand I must set the WRP1AR register to 0xFFXXFFYY where XX is the end page and YY is the ...
-3
votes
1answer
600 views

Uclinux vs Linux [closed]

Searching Internet, I found an operating system called uclinux which can run on ARM Cortex-M7. How is it different from the orginal Linux which runs on PC?? What about librarys such as QT GUI? Is it ...
0
votes
0answers
197 views

Why doesn't my STM32F4 PLL seem to work?

I've spent a few days unsuccessfully trying to get my Nucleo F401RE to use the PLL for its system clock. I've configured it to use the 8MHz HSE and output 84MHz as the system clock. The code stops ...
2
votes
1answer
150 views

Why am I not able to compile this assembly code?

When assembling the code, I get the error : fpu.s(13): error: A1240E: Immediate value cannot be used with this operation ...
0
votes
1answer
59 views

stm32f429 flash load address error

I've recently run into this error where openocd wont flash the binary to my discovery board. I'm using the same linker script that i've been using all along. arm-none-eabi-objdump gives the ...
0
votes
0answers
97 views

Building a simple line out from a mcu DAC

I'd like to get audio (specifically a line out) from a Cortex-M4 10 bit DAC (LPC-4337). The dev board I'm using already has a 470 Ohm resistor in series with the DAC. Since I've never worked with ...
0
votes
0answers
87 views

Infineon XMC4200 alternative pin function for I2C using XMClib

Since i'm unable to post on the infineon XMC forum any more i will try to find help on this forum. I'm working on my first I2C code with the XMC4200 hexagon kit. I'm using Dave4 with the XMCLib. I'm ...
0
votes
0answers
318 views

STM32L4 No UART Message

I've been trying for the past 2 days to get the USART2 controller (pins PD5 & PD6) working on the STM32L476VG Discovery, which allows for UART communication over the ST-LINK cable. I'm using the ...
1
vote
0answers
115 views

MCU wakes up from sleep periodically

I'm facing a weird behavior on SOME boards based upon CC3220SF. Scenario I have 20 units of my custom PCB, designed following the Design Reference Guidelines from Texas Instruments and - like they ...
-2
votes
1answer
385 views

STM32 SYSCLK and CORTEX SYSTEM TIMER [closed]

What is the difference between the two?
1
vote
0answers
327 views

ADC Channel Selection on STM32L476RGT6

I am writing CMSIS based code for STM32L476RGT6(on a Nucleo board) to use the ADC. I have gone through the datasheet but I couldn't find a register to specify the channel for the ADC conversion. How ...
3
votes
1answer
432 views

STM32F4xx bootloader & interrupts

I'm trying to write a bootloader for an STM32F4xx (currently for the STM32F429 discovery board). My application should start at address 0x08020000 while the bootloader starts at 0x08000000 (start of ...
0
votes
2answers
154 views

STM32F4xx Flash Memory Width

I just upgraded a MCU from STM32F407VG to STM32F429VI or 1MB to 2MB When I looked at the linker script I found they allocated 512K for the program. To me that means 16 bit access to memory; 1MB of 32 ...
6
votes
2answers
4k views

What's the difference between setting SysTick Interrupt in NVIC and using it as an exception?

I'm using an STM32F303 MCU and I've noticed that the SysTick can be set up to cause an exception, which seems to mentioned quite often in various User Guides. This way, it will have a priority level ...
1
vote
0answers
429 views

RFFT on 8192 samples in Q15 with CMSIS

I need to perform an FFT on a block of 8192 samples on an STM32F446 microcontroller. For that I wanted to use the CMSIS DSP library as it's available easily and optimised for the STM32F4. My 8192 ...
2
votes
1answer
526 views

Can Cortex M4 data watchpoint trigger an interrupt without a debugger?

I am trying to diagnose memory corruption on a Cortex M4 (Kinetis K64). With the debugger (J-Link) attached I can set data watchpoints and the core will stop when a memory address is written. I want ...
0
votes
2answers
466 views

CORTEX_M4_0: Error connecting to the target: Frequency is out of range [closed]

I tried to burn my coding into the board TM4C123GH6PM using Code Composer v7 (Fedora Linux), it keep showing this error message: "Stellaris In-Circuit Debug Interface /Cortex_M4_0 Error connecting to ...
0
votes
2answers
410 views

ARM Cortex M4f microcontroller on a breadboard

I recently bought an ARM based microcontroller from Texas Instruments (MSP432P401R). However I found out too late that it is not a in a Dual In-line Package and so I cannot use it on a breadboard. ...
1
vote
2answers
526 views

GPIO Access on Cortex-M4 : Read-Modify-Write vs Atomic

I recently came across the Bit-banding feature on Cortex-M4 core and how it provides a solution to avoid race-conditions while toggling bits of registers. The M4 also has a dedicated BSRR register for ...
0
votes
1answer
511 views

FreeRTOS causes SYSTICKACT (HardFault) exception

I generated a basic project with CubeMX for STM32F4. After compiling and having successful run, I added FreeRTOS manually. Unfortunately, all the time I'm getting HardFault exception with SYSTICKACT ...
3
votes
1answer
473 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 ...
1
vote
1answer
920 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 ...
0
votes
2answers
326 views

I2C Communication Signal Issue

hello to all, I'm working on I2C Based Communication Device bq27742-g1(Texas Instrument) Battery fuel gauge which is Slave Device address is 0xAA. I have put in the 10K pull up resistor. In this I'...
0
votes
0answers
237 views

SPI Use inside a Timer interrupt

Microcontroller: XMC4700 Interface: DAVE I would like to send an SPI sequence to an another board in different time intervals. To do that I'm using Dave 4.3.2, the Timer APP and the Interrupt APP. ...
0
votes
0answers
229 views

How to add Lptmr ISR to Interrupt Vector Table for Freescale K60DN board, ARM Cortex M4 Processor

I am attempting to use the low power timer of the Freescale K60 board. I have an interrupt handler written, and now do not know how to add the address of the handler to the interrupt vector table ...
0
votes
0answers
219 views

How to share function or variable address between c and assembly filese in same project using GCC compiler on ARM Cortex M4

I am using a micro-controller with ARM Cortex M4 processor and GCC - GNU ARM compiler. Some functions are written in c in .c file and in assembly in .asm file. My questions are as follows : How can ...
0
votes
1answer
696 views

.elf or .bin file to be download as application code in ARM cortex M4

I am using a MCU with ARM Cortex M4 processor. I Have written a bootloader on it. Using USB CDC ACM class, i am writting the application code in memory address 0x002000. I have generated both .elf ...
-1
votes
2answers
177 views

VxWorks on TI Launchpad Boards

I am trying to find out if VxWorks will be able to run on something similar to the TI EK-TM4C123GXL board (http://www.ti.com/ww/en/launchpad/launchpads-connected-ek-tm4c123gxl.html). It looks like ...
0
votes
1answer
147 views

TM4C123, only one timer works at a time?

I am using TivaC TM4C123 MCU. I am trying to send data serially through one pin and a synchronized clock through another pin. Here is an illustration: I used Timer0 module for the serial data and ...
1
vote
1answer
931 views

JPEG compression on Cortex M4

Is it possible to perform JPEG compression on a Cortex-M4 MCU? Are there existing libraries that can do this and can accept a 10-bit RAW RGB?
0
votes
1answer
330 views

Atmel SWD. Enabling normal GPIO function on the SWO pin

I'm trying to make a project using the ATSAM4LS2A microcontroller (Cortex M4), and i'm using the AtmelICE debugger. The thing is the pinout for the SWD mode also has, beside the SWCLK and SWDIO pins, ...
1
vote
1answer
703 views

Make a Interrupt on a stm32f4xx

I'm new to Cortex M4 and programming on a microcontroller. I'm still learning the basics. I'm using this board (stm32f411re), here is the reference manual. I am trying to make an interrupt on the ...
0
votes
1answer
227 views

How to controll windowed watchdog (WWDG) with dynamically scaling CPU frequencies?

I have a project using ARM Cortex M4 with scaling CPU frequencies dependent on the workload. I would like to use the WWDG because it allows a lot more options like interrupt on watchdog. Question is: ...
1
vote
1answer
685 views

How to use the Non Maskable Interrupt on SAM4S?

I'm trying to use the NMI on a SAM4S (Cortex M4), but I'm finding some hard time to make it work. The main objective is to jump to the NMI handler whenever the power is about to go down, so that I can ...
0
votes
1answer
411 views

My first MCU PCB and a new JTAG Cortex + ETM connector

I am trying to build my own PCB with a Cortex-M4 microcontroller LPC4088. I decided that JTAG still is the easiest option for programming it. But ARM has implemented a new 0.05'' pitch SAMTEC micro ...
4
votes
1answer
3k views

Proper way to wait N cycles in ARM Cortex-M4

After enabling a clock for a certain port you have to wait 4 cycles for the clock to finish initializing. How can one wait for N cycles the proper way? In my code I used this: ...
1
vote
2answers
12k views

STM32F4 TIM2 timer, getting to 1 second

I'm learning a bit about general purpose timers on my STM32F4Discovery board, and would like to know how I can configure the timer to invoke a timer interrupt each second, or at least have the auto-...
2
votes
1answer
956 views

J-link CDC serial port driver problem

I have an on board J-link debugger on my Infineon Relax kit. I'm trying to use my J-link as a serial interface to my PC. It requires CDC serial port driver and I have installed it. Problem is that, I'...
1
vote
1answer
917 views

WFI instruction slowing down SYStick interrupt

I've configured my Infineon relax kit for max frequency(120 MHz). I've set my SYSTick for a periodic interrupt of 10 ms. For power saving, I use a WFI assembler instruction whenever my processor is ...
0
votes
1answer
310 views

stm32f401 hello world code

I've finished designing my STM32f401 board, but I can't get the GPIO to work. After looking for an answer on forums I still can't figure what I'm doing wrong ( Everything worked fine on the ...
0
votes
1answer
104 views

OpenOCD doesn't recognize the Chip ID

I have an issue with openOCD, I want to flash an : ATSAM4S2CA, and Iget this error : ...