The standard technique to enforce atomic access to volatile variables shared with ISRs, via "atomic access guards" or "interrupt guards", in particular when running a bare metal...

I want to know the difference between FIQ and IRQ interrupt system in any microprocessor, e.g: ARM926EJ.

I am looking at some old code from a school project, and in trying to compile it on my laptop I ran into some problems. It was originally written for an old 32 bit version of gcc. Anyway I was tryi...

Based on various references, my subjective definition of signals in Linux is "The triggers that are used to notify the processes about an occurrence of a specific event.Event here may refer to a so...

Note: Since esp8266/Arduino release 3.0.0 ICACHE_RAM_ATTR has been changed to IRAM_ATTR. For future readers, I updated the links to the ESP8266 Arduino Core docs, but left the rest of the question ...

I've seen some flavors of these question around and I've seen mixed answers, still unsure whether they are up-to-date and fully apply to my use case, so I'll ask here. Do let me know if it's a dupl...

When using an RTOS (ex FreeRTOS), we have separate stack spaces for each thread. So what about ISR (Interrupt Service Routines), does they have a separate stack in the memory? Or is this configurab...

I have been trying to create an ISR handler following this tutorial by James Molloy but I got stuck. Whenever I throw a software interrupt, general purpose registers and the data segment register ...

I was wondering if in the following scenario a temporary volatile qualifier would yield correct behavior. Assume an ISR collects values in an array and once enough values have been collected it sig...

Consider the following sequence of micro-operations. MBR ← PC MAR ← X PC ← Y Memory ← MBR Which one of the following is a possible operation performed by this sequence? Instruction fetch...

I'm using AVR-GCC 4.9.2, and I would like to know what happens if I do a premature return in an ISR on an AVR? ISR(USART_RXC_vect) { ... if(idx == BUFSIZE) return; ... } Will the return be ...

I am currently working with Atmel AVR microcontrollers (gcc), but would like the answer to apply to the microcontroller world in general, i.e. usually single-threaded but with interrupts. I know h...

I have an interrupt service routing on the AVR32. I need to read from the interrupt status register in order to cancel the interrupt. However I don't use the result of the read. I'd rather not use ...

I want to understand difference between ISR (Interrupt Service Routine) and Function call. I feel both the function call and ISR are the same from the hardware perspective. Please Correct me if I ...

I should first share all what I know - and that is complete chaos. There are several different questions on the topic, so please don't get irritated :). 1) To find an ISR, CPU is provided with a i...

I am on linux kernel 2.6.32. I am facing an issue in which one of the two ISR (serial and ethernet) are taking more time (hundreds of microseconds) on several occasion/under some scenarios which I ...

When you disable interrupts (with the cli instruction in x86), what exactly happens? Does the PIC wait for you to turn on interrupts, and fire the interrupt when that happens? (If so, how long do...

Any good 68k assembly programmers out there?? I'm using a commercial Green Hills compiler for a Motorola 68040 and I'm seeing some very strange behavior from the code. Sometimes, the code will do a...