• What happens to upper half of 32-bit data bus when reading 16-bit chip?
    Hi guys, I am interested in exploring a scenario when Cortex M4 cpu performs a 16-bit static memory read when 32-bit memory is actually on the board. The 16-bit memory chip is connected to lower half...
  • which library should be used for half-precision mathematic functions?
    Hi all, I want to use half-precision arithmetic on Raspberry pi 3. I installed clang compiler to use _Float16 data type (which is for 16-bit arithmetic purpose). I was wondering is there any library...
  • An algorithm on a M7 is slower than on M4 - why?
    Hi there, we are working on an audio project, where we move some firmware from an STM32F407 (ARM Cortex M4) to an ATSAME70 (ARM Cortex M7). Despite the ATSAME70 runing at 300 MHz, while the STM32F407...
  • ldr 6 cycles on M4 from flash ? (and "weird" constant fetched )
    I'm stepping & cycle checking with the DWT counter, on CM4 Question why is the second LDR here is 6 cycles, Is it because of flash vs SRAM ? And is Flash read always 6 cycles ? And , is it in the...
  • 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...