Char. LCD and 18F452 on 20 MHz not work


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  1. #1
    Join Date
    Jul 2008
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    My english is bad, sorry
    With this code problem is finish.

    Xtal = 20 MHz
    Osc Config = HS

    Need first code:
    Code:
    pause 1000
    LCDOUT $FE,1
    pause 500
    after initialising lcd:
    Code:
    LCDOUT $FE,1,"HELLO WORLD"
    But PAUSE and PAUSEUS working at value/5.

    Example:
    Code:
    PAUSE 5000
    working to 1 Second.

    I edited in "pbppic18.lib" also PAUSE problem is finish.
    with 4 MHz xtal pauseus macro.
    Code:
    ;****************************************************************
    ;* PAUSEUS    : Pause n microseconds at 4MHz                    *
    ;*                                                              *
    ;* Input      : R0 + 1, W = microseconds                        *
    ;* Output     : None                                            *
    ;*                                                              *
    ;* Notes      : minimum 19us                                    *
    ;****************************************************************
    
          if (OSC == 4)
      LIST
    PAUSEUS clrf	R0 + 1		; 1
    PAUSEUSL addlw	-23		; 1 Subtract overhead
                 movwf   R0                        ; 1
    	movlw	-4		; ********changed -1 to -4***********
    	bnc	pauseush	             ; 1 / 2
    	nop			; 1
    pauseusloop CLRWDT?NOP		; 1
    	addwf	R0, F		; 1
    	bc	pauseusloop	; 1 / 2
    	nop			; 1
    pauseush addwf	R0, F		; 1
    	decf	R0 + 1, F	; 1
    	bc	pauseusloop	; 1 / 2
    	btfsc	R0, 0		; 1 / 2
    	bra	$ + 2		; 2 / 0
    	btfss	R0, 1		; 1 / 2
    	bra	pauseusdone	; 2 / 0
    	bra	$ + 2		; 0 / 2
    	nop			; 0 / 1
    pauseusdone return		; 2 + 3 (call + setup)
      NOLIST
          endif
    Thanks for your interesting.

    Best regards.
    Last edited by samettin; - 27th July 2008 at 22:28.

  2. #2
    skimask's Avatar
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    Quote Originally Posted by samettin View Post
    My english is bad, sorry
    It's good enough. Don't worry about it...

    With this code problem is finish.
    Not understanding this statement.
    Problem or No Problem?

    But PAUSE and PAUSEUS working at value/5.
    Example:
    Code:
    PAUSE 5000
    working to 1 Second.
    Which leads me to believe that either you config statements are 'taking effect' or your PIC is actually running on the internal 4Mhz clock vs. the external 20Mhz oscillator.

  3. #3
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    Quote Originally Posted by skimask View Post
    Not understanding this statement.
    Problem or No Problem?
    No problem

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