• RFFT CMSIS-DSP - Fluctuating index
    I am using the Cortex M4 with CMSIS 5.4.0 DSP library. I'm using the arm_rfft_f32() function and the max_arm_f32() function to compute the maximum frequency bin of injected pure sine wave with an external...
  • Does "LDRD" instruction cause "UNDEFINSTR" error on Cortex-M4?
    Dear Experts, I'm working on a freertos project which is running at Cortex-M4 and I'm being troubled by a problme - hard fault. The following is my debugging process: I dump the registers in the...
  • Measuring Cortex-M4 instruction clock cycle counts
    I'm trying to find a reliable method for measuring instruction clock cycles on the STM32F429 MCU that incorporates a Cortex-M4 processor. Part of the challenge is that although the core CPU has no cache...
  • How the current consumption is affected by instruction address
    Hello to all, I am willing to know the variation in the current consumption due to the instruction address. Therefore I have performed two experiments, first time filled the pipeline with a 32-bit instruction...
  • Example of instructions, doesn't use functional unit at all?
    Hello to all, I need a small help with the processor instructions. Can anybody provide me an example where during execution, the functional unit must not be used or it must be deactivated? All data...