bootload.asm

PIC18F452单片机bootloader源代码

	bra	TestNext


Write2Blocks				; Program one HEX line (2 blocks)
	rcall	SetPointers
	rcall	WriteBlock		; Write 2 blocks (16 bytes)
	rcall	WriteBlock


VerifyWrite				; Verify the data		
	rcall	SetPointers
VerifyNext				; Compare
	tblrd	*+
	movf	POSTINC2, W
	xorwf	TABLAT
	bnz	GeneralErr		; Stop if bad verify
	decfsz	COUNTER
	bra	VerifyNext

	bra	StartOfLine		; Go get the next line of data
; *****************************************************************************



; *****************************************************************************
WriteIDLocations
	movff	ADDRESS_UL, TBLPTRU
	rcall	SetPointers
	rcall	WriteBlock
	bra	StartOfLine
; *****************************************************************************



; *****************************************************************************
WriteConfig
	movlw	b'11000100'		; Setup to write fuses
	movwf	EECON1

	rcall	SetPointers
	movff	ADDRESS_UL, TBLPTRU
	movff	DATACNT, COUNTER

WriteNextConfig
	
	movf	POSTINC2, W
	movwf	TABLAT
	tblwt	*
	rcall	StartWrite		; Initiate a write
	
	tblrd 	*+
	decfsz	COUNTER, F
	bra	WriteNextConfig

	bra	StartOfLine
; *****************************************************************************



             
; *****************************************************************************
WriteEEPROM
	movlw	b'00000100'		; Setup to write DataEE
	movwf	EECON1

	rrcf	ADDRESS_H, W
	rrcf	ADDRESS_L, W
	movwf	EEADR

	rcall	SetPointers
	movlw	0x08
	movwf	COUNTER
	
WriteNextEE
	movff	POSTINC2, EEDATA	; Load the data
	movf	POSTINC2, W

	rcall	StartWrite		; Initiate a write

	btfsc	EECON1, WR		; Wait for the write to finish
	bra	$ - 2

	incf	EEADR, F
	decfsz	COUNTER, F
	bra	WriteNextEE

	bra	StartOfLine
; *****************************************************************************
					






; *****************************************************************************
; Reset pointers to program mem and data mem.

_F_SET_PNTR	CODE

SetPointers
	movff	ADDRESS_H, TBLPTRH	; Reset pointer
	movff	ADDRESS_L, TBLPTRL
		
	lfsr	2, DATA_BUFF

	movlw	0x10                //长度为16字节
	movwf	COUNTER

	return
; *****************************************************************************



; *****************************************************************************
; Write a byte to the serial port.

_F_WRT_RS232	CODE

WrRS232
	btfss	PIR1, TXIF		; Write only if TXREG is ready
	bra	WrRS232
	
	movwf	TXREG
	return
; *****************************************************************************



; *****************************************************************************
; Get a character from the serial port.

_F_GET_CHAR	CODE

GetChar
	btfss	PIR1, RCIF
	bra	GetChar			; Retry if no data

	movf	RCREG, W		; Condition the data
	bcf	WREG, 7
	movwf	RXDATA

;	rcall	WrRS232			; Debug, echo data back

	return
; *****************************************************************************



; *****************************************************************************
; Get a byte of data from the serial port.

_F_GET_BYTE	CODE

GetByte
	rcall	GetChar			; Get a character
	rcall	Ascii2Hex		; Convert to hexdecimal
	swapf	RXDATA, W
	movwf	TEMP1

	rcall	GetChar			; Get the next character
	rcall	Ascii2Hex		; Convert to hexdecimal     //字符和16进制之间的转换函数
	movf	TEMP1, W

	iorwf	RXDATA, W		; Assemble the two nibbles  //功能从传口收到的字符转换成16进制数 此字节内容HEX的一个                                                                                                         记录长度
	
	return     
; *****************************************************************************



; *****************************************************************************
; Convert ASCII to HEX.

_F_ASCII_HEX	CODE

Ascii2Hex				; Convert ASCII to Hexdecimal
	movlw	'0'                          //0-9的ACII2码为30-39
	subwf	RXDATA
	movlw	0xF0
	andwf	RXDATA, W
	bz	A2HDone			; If no upper nibble then number only
	movlw	'A'-'0'-0x0A		; else get the letter
	subwf	RXDATA, F
A2HDone	return
; *****************************************************************************



; *****************************************************************************
; Write a block of data to program memory.

_F_WRT_BLOCK	CODE

WriteBlock
	movlw	0x08

Lp1	movff	POSTINC2, TABLAT	; Load the holding registers
	tblwt	*+
	decfsz	WREG, F
	bra	Lp1

	tblrd	*-			; Point back into the block

	movlw	b'10000100'		; Setup writes
	movwf	EECON1

	rcall	StartWrite		; Write the data

	tblrd	*+			; Point to the beginning of the next block

	return
; *****************************************************************************	



; *****************************************************************************
; Unlock and start the write or erase sequence.

_F_START_WRITE

StartWrite
	movlw	0x55			; Unlock
	movwf	EECON2
	movlw	0xAA
	movwf	EECON2
	bsf	EECON1, WR		; Start the write
	nop

	return
; *****************************************************************************





; *****************************************************************************
; Automatic block aligning function with padding
;WriteBlock
;	call	FlushBuffer
;
;	movlw	0x07			; Determine how much of the block to write
;	andwf	TBLPTRL, W
;
;	comf	WREG, F		
;	andlw	0x07
;	incf	WREG, F
;
;Lp1	movff	POSTINC2, TABLAT	; Load the holding registers
;	tblwt	*+
;	decfsz	WREG, F
;	bra	Lp1
;
;	tblrd	*-			; Point back into the block
;
;	rcall	StartWrite		; Write the data
;
;	tblrd	*+			; Point to the beginning of the next block
;
;	return
;
; *****************************************************************************	



; *****************************************************************************
;FlushBuffer				; Clear any data in the holding registers
;
;	movff	TBLPTRL, PRODL		; Copy the LSB of the pointer
;
;	clrf	TBLPTRL
;	setf	TABLAT
;	movlw	0x08			; Clear the buffer
;Lp2	tblwt	*+
;	decfsz	WREG, F
;	bra	Lp2
;
;	movff	PRODL, TBLPTRL		; Restore the LSB of the pointer
;
;	return
; *****************************************************************************





	END