This document discusses the ARMs response to external interrupts. You can read more about operating modes and exceptions here: Exceptions Processor Modes Switching to privileged mode stores copies of the stack pointer (SP), link register (LR), and CPSR in dedicated “shadow registers”, and allows certain privileged actions (like modifying the CSPR). When one of the seven exceptions occur, the corresponding vector is automatically loaded into the PC, and the ARM automatically switches out of User mode and into a corresponding “privileged” operating mode. Each exception type has its own vector, and the vectors are stored in a section of consecutive memory locations called a vector table. They include a system reset, an attempt to execute an undefined instruction, an aborted instruction fetch, an aborted data memory cycle, an aborted hypervisor call, and IRQ and FIQ interrupt signal assertions. ZYNQ’s ARM processor defines seven types of exceptions. The exception handler preserves context (i.e., makes copies of all CPU registers), deals with the event that caused the exception, restores context, and then returns to the normal program flow. That address is called the “exception vector”, and the instruction stored there is typically a jump to an user-written “exception handler” subroutine.
When an exception occurs, the processor interrupts normal program execution, and fetches its next instruction from a specially designated address that corresponds to the type of exception. Then I read the flag recorder to see if there was or not the interrupt and clean this recorder! I do not know if it is resolved or if it is possible.īut I would use this knowledge you posted here.ARM program execution is automatically interrupted when certain exceptions occur, like the assertion of an externally generated interrupt, or the occurrence of an internal fault like an attempt to execute an undefined instruction. (function that will be called when the interruption occurs) So I plan to enable an external interrupt without an ISR. I still have not figured out the reason, but I suspect the interrupt is changing the value of the variable at the same time of some operation with it! it ends up crashing.
I use it to read pulses with a frequency of max 50hzīut with much less than that, the esp locks and resets! It causes bug in my code and I do not know why! I'm having problems with the external interruption! GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, gpio_status) ĪttachInterrupt(digitalPinToInterrupt(PIN), keypress, FALLING) Gpio_status = GPIO_REG_READ(GPIO_STATUS_ADDRESS) To use those API functions, external C headers must be included. Tue 6:26 pm #79958 dfrap wrote:I found that the Interrupt clearing register GPIO_STATUS_W1TC is part of the SDK.
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