1. 问题
- 51单片机全局变量常量的初始化，static code const
- 函数内部静态变量初始化也失败，例如
void fun()
{static int a = 5;printf("a %d\n", a); //输入的不一定是5，是之前这个地址的值（随机值）
}
2. 解决方案
替换STARTUP_MA.A51启动文件
3. 问题启动文件
$NOMOD51
;------------------------------------------------------------------------------
; This file is part of the C51 Compiler package
; Startup Code for the Capital Micro AS1E5 device
; Copyright (c) 2001-2005 Keil Elektronik GmbH and Keil Software, Inc.
; Version 1.00
;
; *** <<< Use Configuration Wizard in Context Menu >>> ***
;------------------------------------------------------------------------------
; STARTUP_AS1E5.A51: This code is executed after processor reset.
;
; To translate this file use A51 with the following invocation:
;
; A51 STARTUP_CME3000.A51
;
; To link the modified STARTUP_CME3000.OBJ file to your application use the following
; Lx51 invocation:
;
; Lx51 your object file list, STARTUP_CME3000.OBJ controls
;
;------------------------------------------------------------------------------CSEG AT 0F8HDB 0FFH,0FFHDB 'DWINT5'EXTRN CODE (?C_START)LJMP ?C_STARTEND4. 新的启动文件
$NOMOD51
;------------------------------------------------------------------------------
; This file is part of the C51 Compiler package
; Copyright (c) 1988-2005 Keil Elektronik GmbH and Keil Software, Inc.
; Version 8.01
;
; *** <<< Use Configuration Wizard in Context Menu >>> ***
;------------------------------------------------------------------------------
; STARTUP.A51: This code is executed after processor reset.
;
; To translate this file use A51 with the following invocation:
;
; A51 STARTUP.A51
;
; To link the modified STARTUP.OBJ file to your application use the following
; Lx51 invocation:
;
; Lx51 your object file list, STARTUP.OBJ controls
;
;------------------------------------------------------------------------------
;
; User-defined <h> Power-On Initialization of Memory
;
; With the following EQU statements the initialization of memory
; at processor reset can be defined:
;
; <o> IDATALEN: IDATA memory size <0x0-0x100>
; <i> Note: The absolute start-address of IDATA memory is always 0
; <i> The IDATA space overlaps physically the DATA and BIT areas.
IDATALEN EQU 80H
;
; <o> XDATASTART: XDATA memory start address <0x0-0xFFFF>
; <i> The absolute start address of XDATA memory
XDATASTART EQU 0
;
; <o> XDATALEN: XDATA memory size <0x0-0xFFFF>
; <i> The length of XDATA memory in bytes.
XDATALEN EQU 0
;
; <o> PDATASTART: PDATA memory start address <0x0-0xFFFF>
; <i> The absolute start address of PDATA memory
PDATASTART EQU 0H
;
; <o> PDATALEN: PDATA memory size <0x0-0xFF>
; <i> The length of PDATA memory in bytes.
PDATALEN EQU 0H
;
;</h>
;------------------------------------------------------------------------------
;
;<h> Reentrant Stack Initialization
;
; The following EQU statements define the stack pointer for reentrant
; functions and initialized it:
;
; <h> Stack Space for reentrant functions in the SMALL model.
; <q> IBPSTACK: Enable SMALL model reentrant stack
; <i> Stack space for reentrant functions in the SMALL model.
IBPSTACK EQU 0 ; set to 1 if small reentrant is used.
; <o> IBPSTACKTOP: End address of SMALL model stack <0x0-0xFF>
; <i> Set the top of the stack to the highest location.
IBPSTACKTOP EQU 0xFF +1 ; default 0FFH+1
; </h>
;
; <h> Stack Space for reentrant functions in the LARGE model.
; <q> XBPSTACK: Enable LARGE model reentrant stack
; <i> Stack space for reentrant functions in the LARGE model.
XBPSTACK EQU 0 ; set to 1 if large reentrant is used.
; <o> XBPSTACKTOP: End address of LARGE model stack <0x0-0xFFFF>
; <i> Set the top of the stack to the highest location.
XBPSTACKTOP EQU 0xFFFF +1 ; default 0FFFFH+1
; </h>
;
; <h> Stack Space for reentrant functions in the COMPACT model.
; <q> PBPSTACK: Enable COMPACT model reentrant stack
; <i> Stack space for reentrant functions in the COMPACT model.
PBPSTACK EQU 0 ; set to 1 if compact reentrant is used.
;
; <o> PBPSTACKTOP: End address of COMPACT model stack <0x0-0xFFFF>
; <i> Set the top of the stack to the highest location.
PBPSTACKTOP EQU 0xFF +1 ; default 0FFH+1
; </h>
;</h>
;------------------------------------------------------------------------------
;
; Memory Page for Using the Compact Model with 64 KByte xdata RAM
; <e>Compact Model Page Definition
;
; <i>Define the XDATA page used for PDATA variables.
; <i>PPAGE must conform with the PPAGE set in the linker invocation.
;
; Enable pdata memory page initalization
PPAGEENABLE EQU 0 ; set to 1 if pdata object are used.
;
; <o> PPAGE number <0x0-0xFF>
; <i> uppermost 256-byte address of the page used for PDATA variables.
PPAGE EQU 0
;
; <o> SFR address which supplies uppermost address byte <0x0-0xFF>
; <i> most 8051 variants use P2 as uppermost address byte
PPAGE_SFR DATA 0A0H
;
; </e>
;------------------------------------------------------------------------------; Standard SFR Symbols
ACC DATA 0E0H
B DATA 0F0H
SP DATA 81H
DPL DATA 82H
DPH DATA 83H
CKCON DATA 8EH
DPC DATA 93H
DAGESEL DATA 94H
D_PAGESEL DATA 95H
T2CON DATA 0C8H
MUX_SEL DATA 0C9H
RAMMODE DATA 0F8HNAME ?C_STARTUP?C_C51STARTUP SEGMENT CODE
?STACK SEGMENT IDATARSEG ?STACKDS 30EXTRN CODE (?C_START)PUBLIC ?C_STARTUPCSEG AT 0
?C_STARTUP: LJMP STARTUP1CSEG AT 0F8HDB 0FFH,0FFH ;加密写 00H 00HDB 'DWINT5'RSEG ?C_C51STARTUPSTARTUP1: ;T5L 初始化必须的代码;MOV DAGESEL,#01H ;MOV D_PAGESEL,#02H ;MOV CKCON,#00H;MOV DPC,#00H;MOV T2CON,#70H;MOV MUX_SEL,#60H ;WDT OFF;MOV RAMMODE,#00H ;释放APP RAM ;一, 在 startup.a51中添加MOV DAGESEL, #01H ;64K代码空间 MOV D_PAGESEL,#02H ;32K xdata 空间 0x8000 -0xffff MOV CKCON, #00H ;cpu运行在1T模式MOV DPC, #00H ;标准模式,需要指令操作xdata 的 dptr 的增减MOV T2CON, #70H ;T2 自动填装;MOV MUX_SEL, #00H ;WDT OFF,MOV MUX_SEL, #60H ;WDT OFF,Uart2引出P04,P05 Uart3引出P06,P07MOV RAMMODE, #00H
;必须在 startup.a51中第一条MOVX 指令之前的任意位置.IF IDATALEN <> 0 MOV R0,#IDATALEN - 1CLR A
IDATALOOP: MOV @R0,ADJNZ R0,IDATALOOP
ENDIFIF XDATALEN <> 0MOV DPTR,#XDATASTARTMOV R7,#LOW (XDATALEN)IF (LOW (XDATALEN)) <> 0MOV R6,#(HIGH (XDATALEN)) +1ELSEMOV R6,#HIGH (XDATALEN)ENDIFCLR A
XDATALOOP: MOVX @DPTR,AINC DPTRDJNZ R7,XDATALOOPDJNZ R6,XDATALOOP
ENDIFIF PPAGEENABLE <> 0MOV PPAGE_SFR,#PPAGE
ENDIFIF PDATALEN <> 0MOV R0,#LOW (PDATASTART)MOV R7,#LOW (PDATALEN)CLR A
PDATALOOP: MOVX @R0,AINC R0DJNZ R7,PDATALOOP
ENDIFIF IBPSTACK <> 0
EXTRN DATA (?C_IBP)MOV ?C_IBP,#LOW IBPSTACKTOP
ENDIFIF XBPSTACK <> 0
EXTRN DATA (?C_XBP)MOV ?C_XBP,#HIGH XBPSTACKTOPMOV ?C_XBP+1,#LOW XBPSTACKTOP
ENDIFIF PBPSTACK <> 0
EXTRN DATA (?C_PBP)MOV ?C_PBP,#LOW PBPSTACKTOP
ENDIFMOV SP,#?STACK-1; This code is required if you use L51_BANK.A51 with Banking Mode 4
;<h> Code Banking
; <q> Select Bank 0 for L51_BANK.A51 Mode 4
#if 0
; <i> Initialize bank mechanism to code bank 0 when using L51_BANK.A51 with Banking Mode 4.
EXTRN CODE (?B_SWITCH0)CALL ?B_SWITCH0 ; init bank mechanism to code bank 0
#endif
;</h>LJMP ?C_STARTEND
)
)
