please dont rip this site

Generic Pointers for MPLAB-C18 Compiler


by Isaac Marino Bavaresco

This file is a replacement for the Microchip MPLAB-C18 library's 'memcpy' function.

It takes advantage of my 'generic pointer' implementation, which may copy from both RAM or ROM (FLASH) to RAM.

The Macros and definitions needed to use the 'generic pointers' are located in the file "genericpointer.h".

Usage example:

#include "genericpointer.h"

void RAM *memcpy( void RAM *dst, const void GENERIC *src, size_t n );

char            Buffer[32];
const char ROM  Msg1[] = "This message is in ROM";
char RAM        Msg2[] = "This message is in RAM.";
char GENERIC    *pMsg;

void SomeFunction( const char GENERIC *p )
    {
    // 'p' is already a generic pointer.
    memcpy( Buffer, p, sizeof Buffer );

    // A rom pointer is essentially a generic pointer.
    memcpy( Buffer, Msg1, sizeof Buffer );

    // A ram pointer needs to be converted.
    memcpy( Buffer, MAKE_GEN_PTR_RAM( Msg2 ), sizeof Buffer );

    // Direct conversion.
    pMsg = Msg1;

    // Conversion needed.
    pMsg = MAKE_GEN_PTR_RAM( Msg2 );

    // A generic pointer may point to RAM or ROM.
    if( IS_GEN_PTR_TO_RAM( pMsg ))
        // We will write through it only if it points to RAM.
        memcpy( (char RAM*)pMsg, p, 16 );
    }

This code works only in extended mode.

;===============================================================================
; Copyright (c) 2007-2008, Isaac Marino Bavaresco
; All rights reserved.
;
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions are met:
;     * Redistributions of source code must retain the above copyright
;       notice, this list of conditions and the following disclaimer.
;     * Neither the name of the author nor the
;       names of its contributors may be used to endorse or promote products
;       derived from this software without specific prior written permission.
;
; THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
; DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
; (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;===============================================================================
; isaacbavaresco@yahoo.com.br
;===============================================================================
#include <P18CXXX.INC>
;===============================================================================
		radix	decimal
;===============================================================================
STRING		CODE
;===============================================================================
n		equ	0
src		equ	2
dst		equ	5

; void RAM *memcpy( void RAM *dst, const void GENERIC *src, size_t n )

		global	memcpy			; {

memcpy:		movff	FSR2L,POSTINC1		; *FSR1++	 = FSR2;
		movff	FSR2H,POSTINC1

		movff	FSR1L,FSR2L		; FSR2		 = FSR1;
		movff	FSR1H,FSR2H
		
		subfsr	2,9			; FSR2		-= 9;

		movf	[dst+0],w		; PROD = FSR0	 = dst;
		movwf	FSR0L,ACCESS
		movwf	PRODL,ACCESS
		movf	[dst+1],w
		movwf	FSR0H,ACCESS
		movwf	PRODH,ACCESS
;-------------------------------------------------------------------------------
		rlcf	[src+2],w		; if( (unsigned short long)src & 0x800000UL )
		bnc	InROM			;    {
;-------------------------------------------------------------------------------
InRAM:		movsf	[n+0],TBLPTRL		;    TBLPTR	 = n;
		movsf	[n+1],TBLPTRH
		
		movf	[src+0],w		;    FSR2	 = src;
		movsf	[src+1],FSR2H
		movwf	FSR2L,ACCESS

		bra	InRAMStart		;    while( TBLPTR-- )

InRAMLoop:	movff	POSTINC2,POSTINC0	;       *FSR0++	 = *FSR2++;

InRAMStart:	movlw	0
		decf	TBLPTRL,f,ACCESS
		subwfb	TBLPTRH,f,ACCESS
		bc	InRAMLoop

		bra	Epilog			;    }
;-------------------------------------------------------------------------------
						; else
						;    {
InROM:		movsf	[src+0],TBLPTRL		;    TBLPTR = src;
		movsf	[src+1],TBLPTRH
		movsf	[src+2],TBLPTRU

		bra	InROMStart		;    while( n-- )

InROMLoop:	tblrd	*+			;       *FSR0++  = *TBLPTR++;
		movff	TABLAT,POSTINC0

InROMStart:	movlw	0
		decf	[n+0],f
		subwfb	[n+1],f
		bc	InROMLoop		;    }
;-------------------------------------------------------------------------------
Epilog:		subfsr	1,1			; FSR2           = *--FSR1;
		movff	POSTDEC1,FSR2H
		movff	INDF1,FSR2L

		return	0			; }
;===============================================================================
		end
;===============================================================================

See also:


file: /Techref/member/IMB-yahoo-J86/memcpy.asm.htm, 5KB, , updated: 2010/4/14 15:12, local time: 2014/7/30 14:13, owner: IMB-yahoo-J86,
TOP NEW HELP FIND: 
54.196.196.108:LOG IN

 ©2014 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE! / 

<A HREF="http://techref.massmind.org/techref/member/IMB-yahoo-J86/memcpy.asm.htm"> memcpy.asm: Implementation of 'memcpy' for Microchip MPLAB-C18 with support for 'generic pointers'</A>

After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.


Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?

 

Welcome to massmind.org!

 

Welcome to techref.massmind.org!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  .