单片机成长之路（51基础篇） - 018 keil51的STARTUP.A51
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STARTUP.A51原始文件：
1 $NOMOD51;Ax51宏汇编器控制命令，禁止预定义的8051。使编译器不使能预定义的;8051符号，避免产生重复定义的错误。 2 ;------------------------------------------------------------------------------ 3 ; This file is part of the C51 Compiler package 4 ; Copyright (c) 1988-2005 Keil Elektronik GmbH and Keil Software, Inc. 5 ; Version 8.01 6 ; 7 ; *** <<< Use Configuration Wizard in Context Menu >>> *** 8 ;------------------------------------------------------------------------------ 9 ; STARTUP.A51: This code is executed after processor reset. 10 ; 11 ; To translate this file use A51 with the following invocation: 12 ; 13 ; A51 STARTUP.A51 14 ; 15 ; To link the modified STARTUP.OBJ file to your application use the following 16 ; Lx51 invocation: 17 ; 18 ; Lx51 your object file list, STARTUP.OBJ controls 19 ; 20 ;------------------------------------------------------------------------------ 21 ; 22 ; User-defined <h> Power-On Initialization of Memory 23 ; 24 ; With the following EQU statements the initialization of memory 25 ; at processor reset can be defined: 26 ; 27 ; <o> IDATALEN: IDATA memory size <0x0-0x100> 28 ; <i> Note: The absolute start-address of IDATA memory is always 0 29 ; <i> The IDATA space overlaps physically the DATA and BIT areas. 30 IDATALEN EQU 80H 31 ; 32 ; <o> XDATASTART: XDATA memory start address <0x0-0xFFFF> 33 ; <i> The absolute start address of XDATA memory 34 XDATASTART EQU 0 35 ; 36 ; <o> XDATALEN: XDATA memory size <0x0-0xFFFF> 37 ; <i> The length of XDATA memory in bytes. 38 XDATALEN EQU 0 39 ; 40 ; <o> PDATASTART: PDATA memory start address <0x0-0xFFFF> 41 ; <i> The absolute start address of PDATA memory 42 PDATASTART EQU 0H 43 ; 44 ; <o> PDATALEN: PDATA memory size <0x0-0xFF> 45 ; <i> The length of PDATA memory in bytes. 46 PDATALEN EQU 0H 47 ; 48 ;</h> 49 ;------------------------------------------------------------------------------ 50 ; 51 ;<h> Reentrant Stack Initialization 52 ; 53 ; The following EQU statements define the stack pointer for reentrant 54 ; functions and initialized it: 55 ; 56 ; <h> Stack Space for reentrant functions in the SMALL model. 57 ; <q> IBPSTACK: Enable SMALL model reentrant stack 58 ; <i> Stack space for reentrant functions in the SMALL model. 59 IBPSTACK EQU 0 ; set to 1 if small reentrant is used. 60 ; <o> IBPSTACKTOP: End address of SMALL model stack <0x0-0xFF> 61 ; <i> Set the top of the stack to the highest location. 62 IBPSTACKTOP EQU 0xFF +1 ; default 0FFH+1 63 ; </h> 64 ; 65 ; <h> Stack Space for reentrant functions in the LARGE model. 66 ; <q> XBPSTACK: Enable LARGE model reentrant stack 67 ; <i> Stack space for reentrant functions in the LARGE model. 68 XBPSTACK EQU 0 ; set to 1 if large reentrant is used. 69 ; <o> XBPSTACKTOP: End address of LARGE model stack <0x0-0xFFFF> 70 ; <i> Set the top of the stack to the highest location. 71 XBPSTACKTOP EQU 0xFFFF +1 ; default 0FFFFH+1 72 ; </h> 73 ; 74 ; <h> Stack Space for reentrant functions in the COMPACT model. 75 ; <q> PBPSTACK: Enable COMPACT model reentrant stack 76 ; <i> Stack space for reentrant functions in the COMPACT model. 77 PBPSTACK EQU 0 ; set to 1 if compact reentrant is used. 78 ; 79 ; <o> PBPSTACKTOP: End address of COMPACT model stack <0x0-0xFFFF> 80 ; <i> Set the top of the stack to the highest location. 81 PBPSTACKTOP EQU 0xFF +1 ; default 0FFH+1 82 ; </h> 83 ;</h> 84 ;------------------------------------------------------------------------------ 85 ; 86 ; Memory Page for Using the Compact Model with 64 KByte xdata RAM 87 ; <e>Compact Model Page Definition 88 ; 89 ; <i>Define the XDATA page used for PDATA variables. 90 ; <i>PPAGE must conform with the PPAGE set in the linker invocation. 91 ; 92 ; Enable pdata memory page initalization 93 PPAGEENABLE EQU 0 ; set to 1 if pdata object are used. 94 ; 95 ; <o> PPAGE number <0x0-0xFF> 96 ; <i> uppermost 256-byte address of the page used for PDATA variables. 97 PPAGE EQU 0 98 ; 99 ; <o> SFR address which supplies uppermost address byte <0x0-0xFF> 100 ; <i> most 8051 variants use P2 as uppermost address byte 101 PPAGE_SFR DATA 0A0H 102 ; 103 ; </e> 104 ;------------------------------------------------------------------------------ 105 106 ; Standard SFR Symbols 107 ACC DATA 0E0H 108 B DATA 0F0H 109 SP DATA 81H 110 DPL DATA 82H 111 DPH DATA 83H 112 113 NAME ?C_STARTUP 114 115 116 ?C_C51STARTUP SEGMENT CODE 117 ?STACK SEGMENT IDATA 118 119 RSEG ?STACK 120 DS 1 121 122 EXTRN CODE (?C_START) 123 PUBLIC ?C_STARTUP 124 125 CSEG AT 0 126 ?C_STARTUP: LJMP STARTUP1 127 128 RSEG ?C_C51STARTUP 129 130 STARTUP1: 131 132 IF IDATALEN <> 0 133 MOV R0,#IDATALEN - 1 134 CLR A 135 IDATALOOP: MOV @R0,A 136 DJNZ R0,IDATALOOP 137 ENDIF 138 139 IF XDATALEN <> 0 140 MOV DPTR,#XDATASTART 141 MOV R7,#LOW (XDATALEN) 142 IF (LOW (XDATALEN)) <> 0 143 MOV R6,#(HIGH (XDATALEN)) +1 144 ELSE 145 MOV R6,#HIGH (XDATALEN) 146 ENDIF 147 CLR A 148 XDATALOOP: MOVX @DPTR,A 149 INC DPTR 150 DJNZ R7,XDATALOOP 151 DJNZ R6,XDATALOOP 152 ENDIF 153 154 IF PPAGEENABLE <> 0 155 MOV PPAGE_SFR,#PPAGE 156 ENDIF 157 158 IF PDATALEN <> 0 159 MOV R0,#LOW (PDATASTART) 160 MOV R7,#LOW (PDATALEN) 161 CLR A 162 PDATALOOP: MOVX @R0,A 163 INC R0 164 DJNZ R7,PDATALOOP 165 ENDIF 166 167 IF IBPSTACK <> 0 168 EXTRN DATA (?C_IBP) 169 170 MOV ?C_IBP,#LOW IBPSTACKTOP 171 ENDIF 172 173 IF XBPSTACK <> 0 174 EXTRN DATA (?C_XBP) 175 176 MOV ?C_XBP,#HIGH XBPSTACKTOP 177 MOV ?C_XBP+1,#LOW XBPSTACKTOP 178 ENDIF 179 180 IF PBPSTACK <> 0 181 EXTRN DATA (?C_PBP) 182 MOV ?C_PBP,#LOW PBPSTACKTOP 183 ENDIF 184 185 MOV SP,#?STACK-1 186 187 ; This code is required if you use L51_BANK.A51 with Banking Mode 4 188 ;<h> Code Banking 189 ; <q> Select Bank 0 for L51_BANK.A51 Mode 4 190 #if 0 191 ; <i> Initialize bank mechanism to code bank 0 when using L51_BANK.A51 with Banking Mode 4. 192 EXTRN CODE (?B_SWITCH0) 193 CALL ?B_SWITCH0 ; init bank mechanism to code bank 0 194 #endif 195 ;</h> 196 LJMP ?C_START 197 198 END
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