what is the CPU clock frequency of MSP430F5635 ?

Hi

If instead of _delay_cycles , if i have to use _nop() for creating some delay ,

what is the time taken to execute one _nop() instruction ??

Please reply .

Thanks in advance.

Jenitta

Hi Jenitta,

the clock frequency is given by your configuration and your crystals used on your board.__delay_cycles(n) is a function that inserts code that needs n cycles of MCLK to run. So if your clock runs at 8MHz a cycles takes 125ns, 1ms delay then need 8000 cycles of delay.

Apart from that, if you need accurate delays you should better use a timer - they are made for this :-)

Hi again,

the _nop() is a special assembler instruction which does No OPeration and will take one MCLK cycle. But be aware that

volatile int i;
for (i=0; i<8000; i++) {
  __nop();
}

and

__delay_cycles(8000);

will have *very* different delay times.

Hi Jenitta,

By default the main clock MCLK is sourced from the DCO and is trimmed by the FLL to ~1MHz using REFO as reference.

See the UCS examples for how to adjust the clocks to your needs.

Also as Jan alluded to, you should use __delay_cycles if you want a cycle accurate delay function.

Tony

Thank you very much !