improving progam executiion speed

[KumarTP]

To improve the execution time of a program being run on the board 'Nucleo-439ZI' from the current 20 ms period to less than 1 ms [more than 20 times reduction]. To reduce the same, I tried to switch the clock frequency source of the timer to HSE (8 MHz) instead of the internal clock (32.768KHz) [That means 24 times higher frequency to improve system latency ]. However, some issues are observed when tried by clicking 'Resolve Clock Issues' could not be resolved.

How can I improve execution time from 20ms to 1 ms?

[KumarTP]

The idea is to reduce program compiling time. Now it is taking 20ms, trying to reduce compiling time from 20ms to 1ms.( need to speed up ) And there are no other peripherals used.

[SofLit]

Compilation time? or execution time??

Unfortunately you add more confusions than clarifying your expectations ..

[KumarTP]

oops sorry, execution time.

[SofLit]

Some tips to speed up program execution:

• Increase the system frequency
• Enable instruction and data cache if the program is executed from the internal Flash:

#if (INSTRUCTION_CACHE_ENABLE != 0U)
  __HAL_FLASH_INSTRUCTION_CACHE_ENABLE();
#endif /* INSTRUCTION_CACHE_ENABLE */

#if (DATA_CACHE_ENABLE != 0U)
  __HAL_FLASH_DATA_CACHE_ENABLE();
#endif /* DATA_CACHE_ENABLE */

#if (PREFETCH_ENABLE != 0U)
  __HAL_FLASH_PREFETCH_BUFFER_ENABLE();
#endif /* PREFETCH_ENABLE */

• You can also use internal RAM for code execution (0-wait-state like).
• Optimize for speed in your IDE

It could be there are some other tips but these are the ones came to my mind at the moment.

[LCE]

Maybe you give us some short description of what your "program" is doing.

And how are you measuring these obscure 20 ms ? 

Maybe you are using polling functions, while-tick-loops, ... so many things that can go wrong. But letting us guess doesn't help us help you. ;)