Erasing uC eeprom through bootloader.

[flote21]

Hello guys!

I have already implemented a the Tiny bootloader in a PIC18F4520 and it is working very good. However I can't only write in the program memory and I don't know if there is any way to erase the internal eeprom memory of the PIC through booltloader.

Thanks.

 

[bigdogguru]

Writing to EEPROM requires different methods from that of writing to flash from within your application code.

What version of the Tiny Bootloader are your utilizing? The latest version, Tiny Multi Bootloader+, appears to have the ability to erase and program the contents of the EEPROM, although I've not tested this feature.

Please post your code with a more thorough explanation of the required task.


BigDog

 

[flote21]

Hi! Thanks for your soon reply!

I am using the version V0.8.3 of here:

http://tinypicbootload.sourceforge.net/

And the ASM code implemented is this one:

	radix DEC

	; change these lines accordingly to your application	
#include "p18f4520.inc"
IdTypePIC = 0x41			; must exists in "piccodes.ini"
#define max_flash 0x8000	; in BYTES!!! (= 'max flash memory' from "piccodes.ini")

#define USE_INTOSC	; change frequency at line 104. If you use an external crystal, comment this line!
xtal EQU 20000000		; you may want to change: _XT_OSC_1H  _HS_OSC_1H  _HSPLL_OSC_1H
baud EQU 115200			; standard TinyBld baud rates: 115200 or 19200
	; The above 5 lines can be changed and built a bootloader for the desired frequency (and PIC type)
	
	;********************************************************************
	;	Tiny Bootloader		18F series		Size=100words
	;	claudiu.chiculita@ugal.ro
	;	http://www.etc.ugal.ro/cchiculita/software/picbootloader.htm
	;	Modified by Nam Nguyen-Quang for testing different PIC18Fs with tinybldWin.exe v1.9
	;	namqn@yahoo.com
	; 
	; modified by Edorul:
	; EEPROM write is only compatible with "Tiny PIC Bootloader+"
	; http://sourceforge.net/projects/tinypicbootload/
	;********************************************************************

;	This source file is for PIC18F2520 and 4520

;	Copy these include files to your project directory (i.e. they are in the same
;	directory with your .asm source file), if necessary

	#include "spbrgselect.inc"	; RoundResult and baud_rate

		#define first_address max_flash-200		;100 words

;----- CONFIG1H Options -----
		CONFIG	OSC = HS, FCMEN = OFF, IESO = OFF
;		CONFIG	OSC = INTIO67, FCMEN = OFF, IESO = OFF	; Use internal oscilator, xtal = 8000000


;----- CONFIG2L Options -----
		CONFIG	PWRT = ON, BOREN = ON, BORV = 2


;----- CONFIG2H Options -----
		CONFIG	WDT = OFF, WDTPS = 128


;----- CONFIG3H Options -----
		CONFIG	MCLRE = ON, LPT1OSC = OFF, PBADEN = OFF, CCP2MX = PORTC

;----- CONFIG4L Options -----
		CONFIG	STVREN = ON, LVP = OFF, DEBUG = OFF, XINST = OFF

;----------------------------- PROGRAM ---------------------------------
	cblock 0
	crc
	i
	cnt1
	cnt2
	cnt3
	counter_hi
	counter_lo
	flag    
	endc
	cblock 10
	buffer:64
	dummy4crc
	endc
	
SendL macro car
	movlw car
	movwf TXREG
	endm
	
;0000000000000000000000000 RESET 00000000000000000000000000

		ORG     0x0000
		GOTO    IntrareBootloader

;view with TabSize=4
;&&&&&&&&&&&&&&&&&&&&&&&   START     &&&&&&&&&&&&&&&&&&&&&&
;----------------------  Bootloader  ----------------------
;PC_flash:		C1h				U		H		L		x  ...  <64 bytes>   ...  crc	
;PC_eeprom:		C1h			   	40h   EEADRH  EEADR     1       EEDATA	crc					
;PC_cfg			C1h			U OR 80h	H		L		1		byte	crc
;PIC_response:	   type `K`
	
	ORG first_address		;space to deposit first 4 instr. of user prog.
	nop
	nop
	nop
	nop
	org first_address+8

IntrareBootloader
							;init IntOSC, added by Nam Nguyen-Quang
#ifdef USE_INTOSC							
	movlw 0x70	; internal 8MHz
	movwf OSCCON
	; the above 2 lines should be commented out for designs not using the internal oscilator
	; or for the chips without the internal oscilator
#endif
							;init serial port
	movlw b'00100100'
	movwf TXSTA
	movlw spbrg_value
	movwf SPBRG
	movlw b'10010000'
	movwf RCSTA
							;wait for computer
	rcall Receive			
	sublw 0xC1				;Expect C1h
	bnz way_to_exit
	SendL IdTypePIC			;send PIC type
MainLoop
	SendL 'K'				; "-Everything OK, ready and waiting."
mainl
	clrf crc
	rcall Receive			;Upper
	movwf TBLPTRU    
		movwf flag			;(for EEPROM and CFG cases)
	rcall Receive			;Hi
	movwf TBLPTRH
	rcall Receive			;Lo
	movwf TBLPTRL
		movwf EEADR			;(for EEPROM case)
	rcall Receive			;count    
	movwf i
	incf i
	lfsr FSR0, (buffer-1)
rcvoct						;read 64+1 bytes
		movwf TABLAT		;prepare for cfg; => store byte before crc
	rcall Receive
	movwf PREINC0
	btfss i,0		;don't know for the moment but in case of EEPROM data presence...
		movwf EEDATA		;...then store the data byte (and not the CRC!)
	decfsz i
	bra rcvoct
	tstfsz crc				;check crc
	bra ziieroare
		btfss flag,6		;is EEPROM data?
		bra noeeprom
		movlw b'00000100'	;Setup eeprom
		rcall Write
		bra waitwre
noeeprom
;----no CFG write in "Tiny PIC Bootloader+"
;		btfss flag,7		;is CFG data?
;		bra noconfig
;		tblwt*				;write TABLAT(byte before crc) to TBLPTR***
;		movlw b'11000100'	;Setup cfg
;		rcall Write
;		bra waitwre
;noconfig
;----
							;write
eraseloop
	movlw	b'10010100'		; Setup erase
	rcall Write
	TBLRD*-					; point to adr-1
	
writebigloop	
	movlw 2					; 2groups
	movwf counter_hi
	lfsr FSR0,buffer
writesloop
	movlw 32				; 32bytes = 16instr
	movwf counter_lo
writebyte
	movf POSTINC0,w			; put 1 byte
	movwf TABLAT
	tblwt+*
	decfsz counter_lo
	bra writebyte
	
	movlw	b'10000100'		; Setup writes
	rcall Write
	decfsz counter_hi
	bra writesloop
waitwre	
	;btfsc EECON1,WR		;for eeprom writes (wait to finish write)
	;bra waitwre			;no need: round trip time with PC bigger than 4ms
	
	bcf EECON1,WREN			;disable writes
	bra MainLoop
	
ziieroare					;CRC failed
	SendL 'N'
	bra mainl
	  
;******** procedures ******************

Write
	movwf EECON1
	movlw 0x55
	movwf EECON2
	movlw 0xAA
	movwf EECON2
	bsf EECON1,WR			;WRITE
	nop
	;nop
	return


Receive
	movlw xtal/2000000+1	; for 20MHz => 11 => 1second delay
							; for 18F2xxx chips, this should be xtal/1000000+1
	movwf cnt1
rpt2						
	clrf cnt2
rpt3
	clrf cnt3
rptc
		btfss PIR1,RCIF			;test RX
		bra notrcv
	    movf RCREG,w			;return read data in W
	    addwf crc,f				;compute crc
		return
notrcv
	decfsz cnt3
	bra rptc
	decfsz cnt2
	bra rpt3
	decfsz cnt1
	bra rpt2
	;timeout:
way_to_exit
	bcf	RCSTA,	SPEN			; deactivate UART
	bra first_address
;*************************************************************
; After reset
; Do not expect the memory to be zero,
; Do not expect registers to be initialised like in catalog.

            END

Writing to EEPROM requires different methods from that of writing to flash from within your application code.

What version of the Tiny Bootloader are your utilizing? The latest version, Tiny Multi Bootloader+, appears to have the ability to erase and program the contents of the EEPROM, although I've not tested this feature.

Please post your code with a more thorough explanation of the required task.


BigDog