以下啟動程序用來替代startup.a51，Maxim提供經(jīng)過測試的軟件代碼(4.8p演示軟件中，啟動程序位于utilstartup_n_safe.a51)，以下列出了程序代碼。

第一次在工廠運行程序時，微調(diào)寄存器的內(nèi)容被復(fù)制到閃存內(nèi)。之后，對微調(diào)寄存器進行測試。一旦測試中發(fā)生失效，程序?qū)⒑唵蔚匕袸C置于休眠模式，然后重新讀取微調(diào)數(shù)據(jù)。喚醒器件操作后，IC會自動讀取微調(diào)“保險絲”內(nèi)的數(shù)值。復(fù)位期間調(diào)用保險絲測試程序，將重新讀取微調(diào)“保險絲”的數(shù)據(jù)并進行修正。

?

;/***************************************************************************
; * This code and information is provided "as is" without warranty of any   *
; * kind, either expressed or implied, including but not limited to the     *
; * implied warranties of merchantability and/or fitness for a particular   *
; * purpose.                                                                *
; *                                                                         *
; * Copyright (C) 2011 Maxim Integrated Products, Inc. All Rights Reserved. *
; ***************************************************************************/
;//**************************************************************************
;//    
;//  DESCRIPTION: 71M652x POWER METER - STARTUP Code.
;//
;//**************************************************************************
;//               
;// File: STARTUP_N_SAFE.A51.
;//               
$NOMOD51
;------------------------------------------------------------------------------
;  This file is part of the C51 Compiler package
;  Copyright (c) 1988-2002 Keil Elektronik GmbH and Keil Software, Inc.
;------------------------------------------------------------------------------
;  STARTUP.A51:  This code is executed after processor reset.
;
;  To translate this file use A51 with the following invocation:
;
;     A51 STARTUP_N_SAFE.A51
;
;  To link the modified STARTUP_N_SAFE.OBJ file to your application use the following
;  BL51 invocation:
;
;     BL51 , STARTUP_N_SAFE.OBJ 
;
;------------------------------------------------------------------------------
;
;  User-defined Power-On Initialization of Memory
;  With the following EQU statements the initialization of memory
;  at processor reset can be defined:
;
;               ; the absolute start-address of IDATA memory is always 0
IDATALEN        EQU     100H    ; the length of IDATA memory in bytes.
;
XDATASTART      EQU     0H      ; the absolute start-address of XDATA memory
XDATALEN        EQU     000H    ; the length of XDATA memory in bytes.
;
PDATASTART      EQU     0H      ; the absolute start-address of PDATA memory
PDATALEN        EQU     0H      ; the length of PDATA memory in bytes.
;
;  Notes:  The IDATA space overlaps physically the DATA and BIT areas of the
;          8051 CPU. At minimum the memory space occupied from the C51 
;          run-time routines must be set to zero.
;------------------------------------------------------------------------------
;
;  Reentrant Stack Initialization
;
;  The following EQU statements define the stack pointer for reentrant
;  functions and initialized it:
;
;  Stack Space for reentrant functions in the SMALL model.
IBPSTACK        EQU     1       ; set to 1 if small reentrant is used.
IBPSTACKTOP     EQU     0FFH+1  ; set top of stack to highest location+1.
;
;  Stack Space for reentrant functions in the LARGE model.      
XBPSTACK        EQU     0       ; set to 1 if large reentrant is used.
XBPSTACKTOP     EQU     07FFH+1; set top of stack to highest location+1.
;
;  Stack Space for reentrant functions in the COMPACT model.    
PBPSTACK        EQU     0       ; set to 1 if compact reentrant is used.
PBPSTACKTOP     EQU     07FFH+1; set top of stack to highest location+1.
;
;------------------------------------------------------------------------------
;  Page Definition for Using the Compact Model with 64 KByte xdata RAM
;
;  The following EQU statements define the xdata page used for pdata
;  variables. The EQU PPAGE must conform with the PPAGE control used
;  in the linker invocation.
;
PPAGEENABLE     EQU     1       ; set to 1 if pdata object are used.
;
PPAGE           EQU     7       ; define PPAGE number.
                PUBLIC  PPAGE_SFR
PPAGE_SFR       DATA    0BFH    ; SFR that supplies uppermost address byte
;               (most 8051 variants use P2 as uppermost address byte)
;------------------------------------------------------------------------------

; Switch to M6520 when chip is available. 

; Standard SFR Symbols 
ACC     DATA    0E0H
B       DATA    0F0H
SP      DATA    81H
DPL     DATA    82H
DPH     DATA    83H
USER1   DATA    90H
DIR1    DATA    91H
FCTRL   DATA    0B2H
IPH     DATA    0B9H
IPL     DATA    0A9H
IRCON   DATA    0C0H
IEN0    DATA    0A8H
IEN1    DATA    0B8H

                NAME    ?C_STARTUP

?C_C51STARTUP   SEGMENT   CODE
?STACK          SEGMENT   IDATA

                RSEG    ?STACK
                DS      1

                EXTRN CODE (?C_START)
                PUBLIC  ?C_STARTUP
                PUBLIC  _?TRIM_TEST

                CSEG    AT      0
?C_STARTUP:     LJMP    STARTUP1
                RSEG    ?C_C51STARTUP
STARTUP1:
                CLR     IEN0^7          ; Disable interrupts
; To enable secure mode, remove the semicolon of the next line
;                ORL    FCTRL,#40H       ; set secure bit
                MOV     0E8h,#0FFh      ; Refresh nonmaskable watchdog.

; Set system interrupt priorities; more frequent are higher priority.
                MOV     IPH,#01DH       ; From code in options_gbl.h, main.c
                MOV     IPL,#00AH       ; From code in options_gbl.h
; Clear PLL_OK interrupt (bit3), and others
                MOV     IRCON,#0
; Enable PLL_OK interrupt
                MOV     DPTR,#2007H     ; Set EX_PLL
                MOV     A,#20H
                MOVX    @DPTR,A
; Enable interrupts
                MOV     IEN1,#08H       ; Enable INT4, the PLL_OK interrupt
                MOV     IEN0,#80H       ; Enable all interrupts

                ACALL   _?TRIM_TEST       ; Test 6521's trims

IF IDATALEN <> 0
                MOV     R0,#IDATALEN - 1
                CLR     A
IDATALOOP:      MOV     @R0,A
                DJNZ    R0,IDATALOOP
ENDIF