LIST P=16F628A, R=DEC

	#include "P16F628A.INC"

	__config  _INTRC_OSC_NOCLKOUT & _LVP_OFF & _WDT_OFF & _PWRTE_ON & _BODEN_ON

        CBLOCK 0x20
		d1
		d2
		eep_byte
		address
		read_back
	ENDC

 	ORG    0x000

	movlw 7
	movwf CMCON		; CMCON=7 set comperators off

	; initialize ports	  __	 __
	movlw b'10010000'	; OE and WE high (disabled)
	movwf PORTA

	clrf address
	clrf eep_byte
	clrf PORTB

	bsf STATUS,RP0          ; bank 1
	bsf OPTION,7		; disable PORTB pull ups
	clrf TRISA
	clrf TRISB
	bcf STATUS,RP0          ; bank 0

loop    call read_ee            ; read byte from pic eeprom
	movwf eep_byte
	movf address,W		; give address to eprom
	movwf PORTA
	movf eep_byte,W		; give data to eprom
	movwf PORTB
	bcf PORTA,4		; eeprom write enable
	call delay		; wait a little
	bsf PORTA,4		; eeprom write disable
	call delay		; generous delays

	bsf STATUS,RP0		; bank1
	movlw b'11111111'
	movwf TRISB		; set portB to inputs
	bcf STATUS,RP0		; bank0

	bcf PORTA,7		; eeprom output enable
	call delay
	movf PORTB,W
	movwf read_back		; read back data from eprom
	call delay
	bsf PORTA,7		; eeprom output disable

	incf address,F		; increase address in eprom

	goto loop

read_ee bsf STATUS,RP0		; Read byte from eeprom
	movf address,W
	movwf EEADR
	bsf EECON1,RD
	movf EEDATA,W		; Store result in w
	bcf STATUS,RP0
	return

delay   movlw	0x1E
	movwf	d1
	movlw	0x4F
	movwf	d2
delay_0 decfsz	d1, f
	goto	$+2
	decfsz	d2, f
	goto	delay_0
	goto	$+1
	nop
	return

	org 2100h
	de "Hello"

	END