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Hi,Could someone tell me, please, what could be the issue if everything works on the -O3 optimization, but on the -O0 it stops working at the entrance to the "main()" function (freeze)?Thanks.
Hi Ronan,It seems that I do not have write access to these memory addresses.I changed the values manually during debugging and the counter has started counting.Can I somehow unblock write access to memory at these addresses?Thanks!
My apologies - I copied an incorrect version, try this:
#define CM_DEMCR (*((volatile uint32_t*)0xE000EDFC)) #define CM_TRCENA_BIT (1UL<<24) #define CM_DWT_LAR (*((volatile uint32_t*)0xE0001FB0)) #define CM_DWT_CONTROL (*((volatile uint32_t*)0xE0001000)) #define CM_DWT_CYCCNTENA_BIT (1UL<<0) #define CM_DWT_CYCCNT (*((volatile uint32_t*)0xE0001004)) void start_cyccnt() { CM_DEMCR |= CM_TRCENA_BIT; CM_DWT_LAR = 0xC5ACCE55; CM_DWT_CONTROL |= CM_DWT_CYCCNTENA_BIT; CM_DWT_CYCCNT = 0; } void stop_cyccnt() { CM_DWT_CONTROL &= ~CM_DWT_CYCCNTENA_BIT; }
I tested the attached with Arm Development Studio 2021.1, and it works well.
this is a function that does something Function took 3131 cycles
m55_cyclecount.zip