RECEIVER_CODE.asm

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;Copyright (c) 2013 Manolis Agkopian		    ;
;See the file LICENCE for copying permission.	    ;
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	PROCESSOR 16F876A
	INCLUDE <P16F876A.INC>

	__config _XT_OSC & _WDT_OFF & _PWRTE_OFF & _CP_OFF & _LVP_OFF & _BODEN_OFF

TMP_TX EQU 0x20 ;VALUE TO HOLD RECEIVED VALUE
COL_CNT EQU 0x21
LINE_CNT EQU 0x22


	ORG 0x000
	GOTO MAIN
	ORG 0x004 ;INTERRUPT VECTOR
	GOTO INTERRUPT
	INCLUDE <LCD_DRIVER.INC>

MAIN:
	CALL LCD_INIT ;FIRST OF ALL WE HAVE TO INITIALIZE LCD
	CLRF LINE_CNT
	MOVLW 0xFF
	MOVWF COL_CNT
	;---USE PORTA AS I/O
	CLRF PORTA
	MOVLW D'7' ;USE PORTA AS I/O
	MOVWF CMCON ;

	BSF STATUS,RP0 ;SWITCH TO BANK1
	CLRF TRISA ;SET ALL PINS OF PORTA AS OUTPUT
	BCF OPTION_REG,7

	;---CONFIGURE PERIPHERAL INTERRUPTS
	MOVLW B'00100000' ;DISABLE ALL PERIPHERAL INTERRUPTS EXCEPT RECEIVER
	MOVWF PIE1 ;PERIPHERAL INTERRUPT ENABLE/DISABLE

	;---CONFIGURE GENERAL INTERRUPTS
	MOVLW B'01000000' ;DISABLE ALL INTERRUPTS EXCEPT PERIPHERAL
	MOVWF INTCON ;INTERRUPT CONTROL REGISTER

	;---CONFIGURE SPBRG FOR DESIRED BAUD RATE
	MOVLW D'51' ;WE WILL USE 4800bps 
	MOVWF SPBRG ;BAUD AT 4MHZ

	;---CONFIGURE TXSTA
	MOVLW B'00100100' ;CONFIGURE TXSTA AS :
	MOVWF TXSTA ;
	;8 BIT TRANSMISSION - 6.BIT
	;TRANSMIT ENABLED - 5.BIT
	;ASYNCHRONOUS MODE - 4.BIT
	;ENABLE HIGH SPEED BAUD RATE - 2.BIT

	BCF STATUS,RP0 ;SWITCH TO BANK0

	MOVLW B'10000000' ;ENABLE SERIAL PORT
	MOVWF RCSTA ;RECEIVE STATUS REG

	CLRF TMP_TX

	BSF INTCON,7 ;ENABLE ALL UNMASKED INTERRUPTS
	BSF RCSTA,4 ;ENABLE USART RECEIVE

MAIN_LOOP: ;CONTINOUS LOOP
	;BTFSC PORTB,4 ;CHECK IF THE BUTTON IS PRESSED
	GOTO MAIN_LOOP ;IF NOT GOTO CONTINOUS LOOP
	;MOVF TMP_TX,W ;LOAD TMP_TX  
	;MOVWF TXREG ;TO TXREG
	;WE LOAD TMP_TX ON THE INTERRUPT ROUTINE,
	;WHEN AN INFORMATION RECEIVED FROM RX.
	;GOTO MAIN_LOOP ;CONTINOUS LOOP

INTERRUPT:
	BCF INTCON,7 ;DISABLE ALL INTERRUPTS
	BTFSS PIR1,5 ;CHECK IF THE RCIF FLAG IS SET
	GOTO QUIT_INT ;IF NOT RETURN BACK TO THE MAIN LOOP
	MOVF RCREG,W ;MOVE THE RECEIVED BYTE TO W
	MOVWF PORTA ;MOVE W TO PORTA
	MOVWF TMP_TX
	BCF PIR1,5
	INCF COL_CNT
	MOVF COL_CNT, W
	XORLW 0x10 ;CHECK IF WE REACHED THE END OF THE LINE
	BTFSS STATUS, Z
	GOTO QUIT_INT ;IF NOT
	
	;ELSE, CHECK IF WE REACHED THE END OF THE COLUMN
	CLRF COL_CNT
	CALL LCD_L2
	INCF LINE_CNT
	MOVF LINE_CNT, W
	XORLW 0x02
	BTFSS STATUS, Z
	GOTO QUIT_INT ;IF NOT
	
	;ELSE
	CLRF LINE_CNT
	CALL LCD_CLR
	CALL LCD_L1
	
	
QUIT_INT:
	MOVF TMP_TX, W
	CALL LCD_CHAR ;LCD_CHAR WRITES AN ASCII CODE CHAR TO THE LCD, THE LCD uC WILL THEN AUTOINCREMENT THE CURSOR
	RETFIE

	END