How to calculate the delay?

how to calculate the delay for each instruction?



The above listing is taken from the MPLAB (compiled with CCS compiler).
I am using 8Mhz resonator.


Each instruction clock takes 4 clock cycles = 1 /(8 MHz / 4 ) = 0.5 us
GOTO takes 2 instruction clocks
DECFSZ + GOTO loop for 119 times (0x77 = 119) = (1 + 2) x 119 x 0.5 us = 178.5 us
MOVLW + MOVWF + NOP + NOP = 4 x 0.5us = 2 us
The total time spent = 178.5us + 2us = 180.5 us

Is the calculation correct?
I am expecting 90 us, the calculation give me 180.5 us.

Did you set MPLABs (or CCS) to use 8Mhz clock?

MOVLW+MOVWF+NOP+NOP=4 cycles
DECFSZ (no skip)+GOTO=58*(1+2) cycles
DECFSZ (skip) = 2 cycles
Total=180 cycles

Since 1 cycles=0.5us
180cycles=90us

P.S. 0x3B=59

Sorry for my mistake,
the 0x77 is referring to file address, and the value is 0x3B = 59.