/*------------------------------------------------------------------------- _gptrget.c - get value for a generic pointer Copyright (c) 1999, Sandeep Dutta . sandeep.dutta@usa.net This library is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this library; see the file COPYING. If not, write to the Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. As a special exception, if you link this library with other files, some of which are compiled with SDCC, to produce an executable, this library does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. -------------------------------------------------------------------------*/ /* not all devices use P2 to page pdata memory, therefore __XPAGE was introduced. On some targets __XPAGE itself is a paged SFR so it is not safe for all platforms to set this. Furthermore some targets can be configured to behave differently for movx @dptr vs. movx @Ri (don't drive high byte of address bus for movx @Ri only) */ #define USE_PDATA_PAGING_REGISTER 0 __sbit __at (0xF7) B_7; __sbit __at (0xF6) B_6; __sbit __at (0xF5) B_5; /* the return value is expected to be in acc, and not in the standard * location dpl. Therefore we choose return type void here: */ #if defined DSDCC_MODEL_HUGE void _gptrget (char *gptr) __naked { /* This is the banked version with pointers up to 23 bits. B cannot be trashed */ gptr; /* hush the compiler */ __asm ; ; depending on the pointer type acc. to SDCCsymt.h ; jb _B_7,codeptr$ ; >0x80 code ; 3 jnb _B_6,xdataptr$ ; <0x40 far ; 3 mov dph,r0 ; save r0 independant of regbank ; 2 mov r0,dpl ; use only low order address ; 2 jb _B_5,pdataptr$ ; >0x60 pdata ; 3 ; ; Pointer to data space ; mov a,@r0 ; 1 dataptrrestore$: mov r0,dph ; restore r0 ; 2 mov dph,#0 ; restore dph ; 2 ret ; 1 ; ; pointer to external stack or pdata ; pdataptr$: movx a,@r0 ; 1 sjmp dataptrrestore$ ; 2 ; ; pointer to code area ; codeptr$: ; implementation for SiLabs C8051F12x mov a,b ; 2 anl a,#0x03 ; 2 swap a ; 1 push _PSBANK ; 2 anl _PSBANK,#0x0F ; 3 orl _PSBANK,a ; 2 clr a ; 1 movc a,@a+dptr ; 1 pop _PSBANK ; 2 ret ; 1 ; ; pointer to xternal data ; xdataptr$: ; implementation for xram a16-a21 tied to P3 mov _P3,b ; 3 movx a,@dptr ; 1 ret ; 1 ;=== ;44 bytes __endasm; } #elif defined DSDCC_MODEL_MEDIUM void _gptrget (char *gptr) __naked { /* This is the non-banked version with pointers up to 15 bits. Assumes B is free to be used */ gptr; /* hush the compiler */ __asm ; ; depending on the pointer type acc. to SDCCsymt.h ; mov b,dph ; 3 jb _B_7,codeptr$ ; >0x80 code ; 3 jnb _B_6,xdataptr$ ; <0x40 far ; 3 mov b,r0 ; save r0 independant of regbank ; 2 mov r0,dpl ; use only low order address ; 2 jb _B_5,pdataptr$ ; >0x60 pdata ; 3 ; ; Pointer to data space ; mov a,@r0 ; 1 mov r0,b ; restore r0 ; 2 ret ; 1 ; ; pointer to xternal stack or pdata ; pdataptr$: movx a,@r0 ; 1 mov r0,b ; restore r0 ; 2 ret ; 1 ; ; pointer to code area, max 15 bits ; codeptr$: ; 0x8000 <= dptr <= 0xFFFF ; no need to AND dph and restore from B if hardware wraps code memory anl dph,#0x7F ; 3 clr a ; 1 movc a,@a+dptr ; 1 mov dph,b ; 3 ret ; 1 ; ; pointer to xternal data, max 14 bits ; xdataptr$: ; 0 <= dptr <= 0x3FFF movx a,@dptr ; 1 ret ; 1 ;=== ;35 bytes __endasm; } #else void _gptrget (char *gptr) __naked { /* This is the new version with pointers up to 16 bits. B cannot be trashed */ gptr; /* hush the compiler */ __asm ; ; depending on the pointer type acc. to SDCCsymt.h ; jb _B_7,codeptr$ ; >0x80 code ; 3 jnb _B_6,xdataptr$ ; <0x40 far ; 3 mov dph,r0 ; save r0 independant of regbank ; 2 mov r0,dpl ; use only low order address ; 2 jb _B_5,pdataptr$ ; >0x60 pdata ; 3 ; ; Pointer to data space ; mov a,@r0 ; 1 dataptrrestore$: mov r0,dph ; restore r0 ; 2 mov dph,#0 ; restore dph ; 2 ret ; 1 ; ; pointer to xternal stack or pdata ; pdataptr$: movx a,@r0 ; 1 sjmp dataptrrestore$ ; 2 ; ; pointer to code area, max 16 bits ; codeptr$: clr a ; 1 movc a,@a+dptr ; 1 ret ; 1 ; ; pointer to xternal data, max 16 bits ; xdataptr$: movx a,@dptr ; 1 ret ; 1 ;=== ;27 bytes __endasm; } #endif #ifdef __SDCC_ds390 /* the return value is expected to be in acc/_ap, and not in the standard * location dpl/dph. Therefore we choose return type void here: */ void _gptrgetWord (unsigned *gptr) { gptr; /* hush the compiler */ __asm ; ; depending on the pointer type acc. to SDCCsymt.h ; jb _B_7,00003$ ; >0x80 code jnb _B_6,00002$ ; <0x40 far mov dph,r0 ; save r0 independant of regbank mov r0,dpl ; use only low order address jb _B_5,00004$ ; >0x60 pdata ; ; Pointer to data space ; mov _ap,@r0 inc r0 mov a,@r0 inc dpl sjmp 00005$ ; ; pointer to xternal data ; 00002$: movx a,@dptr mov _ap,a inc dptr movx a,@dptr sjmp 00006$ ; ; pointer to code area ; 00003$: clr a movc a,@a+dptr mov _ap,a clr a inc dptr movc a,@a+dptr sjmp 00006$ ; ; pointer to xternal stack ; 00004$: movx a,@r0 mov _ap,a inc r0 movx a,@r0 inc dpl ; ; restore and return ; 00005$: mov r0,dph ; restore r0 mov dph,#0 ; restore dph 00006$: xch a,_ap __endasm; } #endif