how do I speed up an existing pic18f2525 program ?

[Acetronics2]

Hi,

1) I do not think you have to modify the OSCTUNE register ...

2) Place PAUSE 1000 AFTER " DEFINE OSC ..."

3) You can use PLL x 4 Setting, with a 10 to 16 Mhz Xtal ... will give 40 to 64 Mhz Osc speed. Should be enough ...
40 and 48 Mhz are commonly admitted ... 64 is experimental ... but works fine !!!

You first have to change your 18F2525.inc file ( in the PBP/ INC folder ) for :

;****************************************************************
;*  18F2525.INC                                                 *
;*                                                              *
;*  By        : Leonard Zerman, Jeff Schmoyer                   *
;*  Notice    : Copyright (c) 2008 microEngineering Labs, Inc.  *
;*              All Rights Reserved                             *
;*  Date      : 09/15/08                                        *
;*  Version   : 2.60                                            *
;*  Notes     :                                                 *
;****************************************************************
        NOLIST
    ifdef PM_USED
        LIST
        "Error: PM does not support this device.  Use MPASM."
        NOLIST
    else
        LIST
        LIST p = 18F2525, r = dec, w = -311, w = -230, f = inhx32
        INCLUDE "P18F2525.INC" ; MPASM  Header
        ;__CONFIG    _CONFIG1H, _OSC_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
        ;__CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
        ;__CONFIG    _CONFIG3H, _CCP2MX_PORTC_3H & _PBADEN_OFF_3H 
_LPT1OSC_OFF_3H & _MCLRE_ON_3H
        ;__CONFIG    _CONFIG4L,  _STVREN_ON_4L & _LVP_OFF_4L & _XINST_OFF_4L
  Messg " Think to WRITE the correct  CONFIGURATION ... "
  Messg " Think to WRITE the correct  CONFIGURATION ... "
  Messg " Think to WRITE the correct  CONFIGURATION ... "
        NOLIST
    endif
        LIST
EEPROM_START EQU 0F00000h
BLOCK_SIZE EQU 64

THEN

add to the top of your code, just past the Header :

'*****************************************************************************
'Config processeur
'*****************************************************************************
@   __CONFIG    _CONFIG1H, _IESO_OFF_1H & _OSC_HSPLL_1H & _FCMEN_OFF_1H
@   __CONFIG    _CONFIG2L, _BOREN_OFF_2L & _PWRT_ON_2L
@   __CONFIG    _CONFIG2H, _WDT_OFF_2H & _WDTPS_128_2H
@   __CONFIG    _CONFIG3H, _MCLRE_ON_3H & _LPT1OSC_OFF_3H & _PBADEN_OFF_3H & _CCP2MX_PORTBE_3H
@   __CONFIG    _CONFIG4L, _STVREN_OFF_4L & _LVP_OFF_4L & _DEBUG_OFF_4L & _XINST_OFF_4L
@   __CONFIG    _CONFIG5L, _CP0_OFF_5L & _CP1_OFF_5L
@   __CONFIG    _CONFIG5H, _CPB_OFF_5H & _CPD_OFF_5H
@   __CONFIG    _CONFIG6L, _WRT0_OFF_6L & _WRT1_OFF_6L
@   __CONFIG    _CONFIG6H, _WRTB_OFF_6H & _WRTC_OFF_6H & _WRTD_OFF_6H 
@   __CONFIG    _CONFIG7L, _EBTR0_OFF_7L & _EBTR1_OFF_7L
@   __CONFIG    _CONFIG7H, _EBTRB_OFF_7H

You'll have to use " DEFINE OSC xx " Where XX will be 4 x your choosen Xtal frequency.

an also think to modify Serin2/Serout2 to match your Osc speed ...

after that ... check your program flow ... if not enough !!!

Alain