startup.a51

用C51制作的红外通讯装置

; $Id: //depot/software/SDK1/UV2/C51/lib/Triscend/STARTUP.A51#2 $
;------------------------------------------------------------------------------
;  This file is originally part of the C51 Compiler package
;  Copyright (c) 1988-1999 Keil Elektronik GmbH and Keil Software, Inc.
;
;  This file is modified for Triscend Corporation's E5 CSoC device family.
;------------------------------------------------------------------------------
;  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
;  BL51 invocation:
;
;     BL51 <your object file list>, STARTUP.OBJ <controls>
;
;------------------------------------------------------------------------------
;
;  Internal SRAM size (length) of various E5 devices
TE502LEN	EQU 02000H	;  8KB
TE505LEN	EQU 04000H	; 16KB
TE512LEN	EQU 08000H	; 32KB
TE520LEN	EQU 0A000H	; 40KB
;
;  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	0H	; the length of XDATA memory in bytes.
;	If the program runs from external parallel memory (FLASH, SRAM),
;	then XDATALEN should not be larger than the maximum internal RAM size
;	of the E5 device. For example, XDATALEN should not be larger than 40K
;	for E520 (XDATALEN EQU TE520LEN).
;
;   As a result, the E5 specific configuration registers in the top 4KB
;   of XDATA, and the memory-mapped registers in CSL will not be written to.
;   Such registers should be initialized properly elsewhere.
;
;	If the program runs from external serial memory (serial EEPROM) or from
;	internal RAM, then XDATALEN should even be smaller, because some of the
;	internal RAM locations are used to store code.
;   
; NOTE: The upper 4K of XDATA contains E5-specific configuration registers.
;       DO NOT overwrite these locations during initialization.
;
PDATASTART	EQU	0H	; the absolute start-address of PDATA memory
PDATALEN	EQU	0H	; the length of PDATA memory in bytes.
;   Note that PDATA cannot be used if port P2 is exported using the 
;   "8032-style PIO Port" module.
;
;  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 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.
;	If the program runs from external parallel memory (FLASH, SRAM),
;	then XBPSTACKTOP should not be larger than the maximum internal RAM size
;	of the E5 device. For example, XBPSTACKTOP should not be larger than 40K
;	for E520 (XBPSTACKTOP EQU TE520LEN).
;	If the program runs from external serial memory (serial EEPROM) or from
;	internal RAM, then XBPSTACKTOP should even be smaller, because some of the
;	internal RAM locations are used to store code.
;
;  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	1

		EXTRN CODE (?C_START)
		PUBLIC	?C_STARTUP

		CSEG	AT	0
?C_STARTUP:	LJMP	STARTUP1

		RSEG	?C_C51STARTUP

STARTUP1:

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

IF XDATALEN <> 0
		MOV	DPTR,#XDATASTART
		MOV	R7,#LOW (XDATALEN)
  IF (LOW (XDATALEN)) <> 0
		MOV	R6,#(HIGH XDATALEN) +1
  ELSE
		MOV	R6,#HIGH (XDATALEN)
  ENDIF
		CLR	A
XDATALOOP:	MOVX	@DPTR,A
		INC	DPTR
		DJNZ	R7,XDATALOOP
		DJNZ	R6,XDATALOOP
ENDIF

IF PPAGEENABLE <> 0
		MOV	P2,#PPAGE
ENDIF

IF PDATALEN <> 0
		MOV	R0,#PDATASTART
		MOV	R7,#LOW (PDATALEN)
		CLR	A
PDATALOOP:	MOVX	@R0,A
		INC	R0
		DJNZ	R7,PDATALOOP
ENDIF

IF IBPSTACK <> 0
EXTRN DATA (?C_IBP)

		MOV	?C_IBP,#LOW IBPSTACKTOP
ENDIF

IF XBPSTACK <> 0
EXTRN DATA (?C_XBP)

		MOV	?C_XBP,#HIGH XBPSTACKTOP
		MOV	?C_XBP+1,#LOW XBPSTACKTOP
ENDIF

IF PBPSTACK <> 0
EXTRN DATA (?C_PBP)
		MOV	?C_PBP,#LOW PBPSTACKTOP
ENDIF

		MOV	SP,#?STACK-1
		LJMP	?C_START

		END