Char. LCD and 18F452 on 20 MHz not work

[samettin]

Char. LCD and 18F452 on 4 MHz working, but on 20 MHz not work.

Please help me.

define LCD_BITS 4
DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTC
DEFINE LCD_RSBIT 6
DEFINE LCD_EREG PORTC
DEFINE LCD_EBIT 7
DEFINE LCD_LINES 4
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50


LCDOUT $FE,1,"HELLO WORLD"

[mackrackit]

Did you tell PBP that you are using 20 mhz

DEFINE OSC 20

[samettin]

Did you tell PBP that you are using 20 mhz

DEFINE OSC 20

Yes mackrackit.
And OSC = HS
But PBP not compile 18f452 to hex, MPASM compiling to hex. And MPASM compiling on (default) 4 MHz only.

[mackrackit]

Yes mackrackit.

But PBP not compile 18f452 to hex, MPASM compiling to hex. And MPASM compiling on (default) 4 MHz only.

MPASM is required for 18s.
How do you know it is doing 4 MHz? Did you change the congig (*.inc) to HS?

[samettin]

I m sorry, i changed my message

I did change OSC to HS.

LCD vorking with 18F452 on 4 MHz xtal and osc config = XT.

Problem is, if PLL enable with 4 MHz XTAL, or 20 MHz with osc config=HS then.

[mackrackit]

Could you post all of the code and config, not what you think the configs are set for, but a copy paste of the *.inc.

[skimask]

Problem is, if PLL enable with 4 MHz XTAL, or 20 MHz with osc config=HS then.

Might want to also keep in mind that the PLL doesn't work above 10Mhz. The max speed of the PIC is 40Mhz (10 x 4xPLL). Try as you might, you won't get the PIC to run at 160Mhz! (It would be nice, but it won't work )

[samettin]

My english is bad, sorry
With this code problem is finish.

Xtal = 20 MHz
Osc Config = HS

Need first code:

pause 1000
LCDOUT $FE,1
pause 500

after initialising lcd:

LCDOUT $FE,1,"HELLO WORLD"

But PAUSE and PAUSEUS working at value/5.

Example:

PAUSE 5000

working to 1 Second.

I edited in "pbppic18.lib" also PAUSE problem is finish.
with 4 MHz xtal pauseus macro.

;****************************************************************
;* 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.

[samettin]

Might want to also keep in mind that the PLL doesn't work above 10Mhz. The max speed of the PIC is 40Mhz (10 x 4xPLL). Try as you might, you won't get the PIC to run at 160Mhz! (It would be nice, but it won't work )

160Mhz?
Sorry i dont see.

With 4 MHz and PLL 4X4 = 16 MHz.
20 MHz is without PLL. This osc conf. is XT.

[mackrackit]

160Mhz?
Sorry i dont see.

With 4 MHz and PLL 4X4 = 16 MHz.
20 MHz is without PLL. This osc conf. is XT.

Thought you said it was set for HS. XT will not work. Me thinks.

[skimask]

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:

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.

[samettin]

Not understanding this statement.
Problem or No Problem?

No problem