Hi,

I am using the following code on a PIC16F877 @ 4MHz:

 bsf PORTB, 4
 bsf PORTB, 1  ;---------------------
 ; delay for at least 2ms
 movlw 0x95
 movwf Dlay
 movlw 0x02
 movwf Dlay + 1
 decfsz Dlay
  goto $ - 1
 decfsz Dlay + 1
  goto $ - 3

 bcf PORTB, 4 ; --------------------

I intended for 2ms to elapse  between the execution of the dashed lines.
My formula: 1us per instruction
3us per subtraction iteration
2000us / 3us = 667 cycles
667 - 6 (overhead instructions) = 0x295

When I measured this on an oscilloscope, the actual delay came to be 1.2 ms.
If anything, it should be greater than 2 ms because I did not take the extra
cycles that occur each borrow.  Does each subtraction that does not borrow
take 3us to complete? (1us for decfsz, 2us for goto)

Thanks,
-Mike

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