startup.a51

基于USB2.0芯片 ISP1581 的扫描仪固件源码,USB驱动模块

;------------------------------------------------------------------------------
;  This file is part of the C-51 Compiler package
;  Copyright KEIL ELEKTRONIK GmbH 1990
;------------------------------------------------------------------------------
;  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
;  L51 invocation:
;
;     L51 <your object file list>, STARTUP.OBJ <controls>
;
;------------------------------------------------------------------------------
;
;  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
;SP			EQU	81H
IDATALEN	EQU	80H	; the length of IDATA memory in bytes.
;
XDATASTART	EQU	0H	; the absolute start-address of XDATA memory
XDATALEN	EQU	0FFH	; 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 C-51 
;          run-time routines must be set to zero.
;------------------------------------------------------------------------------
;
;  Reentrant Stack Initilization
;
;  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	0	; 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	0FFFFH+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	0FFFFH+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	0	; set to 1 if pdata object are used.
PPAGE		EQU	0	; define PPAGE number.
;
;------------------------------------------------------------------------------

		NAME	?C_STARTUP


?C_C51STARTUP	SEGMENT   CODE
?STACK		SEGMENT   IDATA

		RSEG	?STACK
		DS	80

		EXTRN CODE (Main)
		PUBLIC	?C_STARTUP

		CSEG	AT	0
?C_STARTUP:	LJMP	STARTUP1

		RSEG	?C_C51STARTUP

STARTUP1:

		MOV	R0,#00h
		MOV	R1,#0ffh

CLEARRAM:

		MOV @R0,#00h
		INC	R0
		DJNZ R1,CLEARRAM

 		MOV	SP,#?STACK-1
		LJMP	Main

		END