;
; eeprom.inc: data eeprom helper functions
;
; author: Marko Kanala, raato ]a t[ mulletronic.com
;
; LICENSE
; Creative Commons Attribution-NonCommercial-ShareALike 2.5
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; Copyright: Marko Kanala (raato@mulletronic.com).
;

;
; loads a value from eeprom address in WREG.
;
; value read should be read from EEDATA register.
;
eeprom_load:
	movwf	EEADR
	bcf		EECON1, EEPGD	; access data eeprom
	bcf		EECON1, CFGS	; ...
	bsf		EECON1, RD		; initiate read
	return

;
; saves a value to eeprom.
;
; data to be written should be loaded to EEDATA register.
; eeprom address should be loaded to WREG.
eeprom_save:
	movwf	EEADR
	bcf		EECON1, EEPGD	; access data eeprom
	bcf		EECON1, CFGS	; ...
	bsf		EECON1, WREN	; enable writes

	bcf		INTCON, GIE		; disable interrupts
	movlw	0x55			; initiate
	movwf	EECON2
	movlw	0xaa
	movwf	EECON2
	bsf		EECON1, WR		; ... write
eeprom_save_wait:
	clrwdt
	btfsc	EECON1, WR		; wait for write to finish
	bra		eeprom_save_wait
	bsf		INTCON, GIE		; enable interrupts
	bcf		EECON1, WREN	; disable writes
	return