; *******************************************************************
; BLINKER.ASM
; slow sine blinker
; *******************************************************************
;
; 2004 Copyright by Frank Buss
; *******************************************************************
;
			LIST	P=16F84

#include "P16F84.INC"

			org 0

; global variables
PWM_COUNT	EQU	H'10'
TMP			EQU	H'11'
PWM_INDEX	EQU	H'12'

; misc defines
W			EQU	D'0'
F			EQU	D'1'


; program start

; init
			clrf	STATUS
			clrf	INTCON
			bcf		STATUS, RP0	; select bank 0
			movlw	D'0'		; set levels low
			movwf	PORTA		;  for port a
			movwf	PORTB		;  and port b
			movlw	B'11100000'	; set bits 0-4 port a as output
			bsf		STATUS, RP0	; select bank 1
			movwf	TRISA - H'80'
			movwf	TRISB - H'80'
			bcf		STATUS, RP0	; select bank 0

; main loop
DELAY1		call	GET_PWM
			movwf	PWM_COUNT
			movwf	TMP
DELAY1_LOOP	decf	TMP, F
			btfss	STATUS, Z	; skip if zero is set
			goto	DELAY1_LOOP
			movlw	D'0'		; set levels low
			movwf	PORTA		;  for port a

DELAY2		movf	PWM_COUNT, W
			sublw	D'0'
			movwf	TMP
DELAY2_LOOP	decf	TMP, F
			btfss	STATUS, Z	; skip if zero is set
			goto	DELAY2_LOOP
			movlw	D'255'		; set levels high
			movwf	PORTA		;  for port a
			incf	PWM_INDEX, F
			goto	DELAY1


; PWM table

GET_PWM		movlw	high PWM_TABLE
			movwf	PCLATH
			movf	PWM_INDEX, W
			movwf	PCL			; change PC to the PWM_TABLE entry

			org H'100'

PWM_TABLE	retlw H'80'
			retlw H'83'
			retlw H'86'
			retlw H'89'
			retlw H'8C'
			retlw H'8F'
			retlw H'92'
			retlw H'95'
			retlw H'98'
			retlw H'9B'
			retlw H'9E'
			retlw H'A1'
			retlw H'A4'
			retlw H'A7'
			retlw H'AA'
			retlw H'AD'
			retlw H'B0'
			retlw H'B3'
			retlw H'B5'
			retlw H'B8'
			retlw H'BB'
			retlw H'BE'
			retlw H'C0'
			retlw H'C3'
			retlw H'C6'
			retlw H'C8'
			retlw H'CB'
			retlw H'CD'
			retlw H'CF'
			retlw H'D2'
			retlw H'D4'
			retlw H'D6'
			retlw H'D9'
			retlw H'DB'
			retlw H'DD'
			retlw H'DF'
			retlw H'E1'
			retlw H'E3'
			retlw H'E5'
			retlw H'E7'
			retlw H'E8'
			retlw H'EA'
			retlw H'EC'
			retlw H'ED'
			retlw H'EF'
			retlw H'F0'
			retlw H'F1'
			retlw H'F3'
			retlw H'F4'
			retlw H'F5'
			retlw H'F6'
			retlw H'F7'
			retlw H'F8'
			retlw H'F9'
			retlw H'FA'
			retlw H'FA'
			retlw H'FB'
			retlw H'FC'
			retlw H'FC'
			retlw H'FD'
			retlw H'FD'
			retlw H'FD'
			retlw H'FD'
			retlw H'FD'
			retlw H'FE'
			retlw H'FD'
			retlw H'FD'
			retlw H'FD'
			retlw H'FD'
			retlw H'FD'
			retlw H'FC'
			retlw H'FC'
			retlw H'FB'
			retlw H'FA'
			retlw H'FA'
			retlw H'F9'
			retlw H'F8'
			retlw H'F7'
			retlw H'F6'
			retlw H'F5'
			retlw H'F4'
			retlw H'F3'
			retlw H'F1'
			retlw H'F0'
			retlw H'EF'
			retlw H'ED'
			retlw H'EC'
			retlw H'EA'
			retlw H'E8'
			retlw H'E7'
			retlw H'E5'
			retlw H'E3'
			retlw H'E1'
			retlw H'DF'
			retlw H'DD'
			retlw H'DB'
			retlw H'D9'
			retlw H'D6'
			retlw H'D4'
			retlw H'D2'
			retlw H'CF'
			retlw H'CD'
			retlw H'CB'
			retlw H'C8'
			retlw H'C6'
			retlw H'C3'
			retlw H'C0'
			retlw H'BE'
			retlw H'BB'
			retlw H'B8'
			retlw H'B5'
			retlw H'B3'
			retlw H'B0'
			retlw H'AD'
			retlw H'AA'
			retlw H'A7'
			retlw H'A4'
			retlw H'A1'
			retlw H'9E'
			retlw H'9B'
			retlw H'98'
			retlw H'95'
			retlw H'92'
			retlw H'8F'
			retlw H'8C'
			retlw H'89'
			retlw H'86'
			retlw H'83'
			retlw H'80'
			retlw H'7C'
			retlw H'79'
			retlw H'76'
			retlw H'73'
			retlw H'70'
			retlw H'6D'
			retlw H'6A'
			retlw H'67'
			retlw H'64'
			retlw H'61'
			retlw H'5E'
			retlw H'5B'
			retlw H'58'
			retlw H'55'
			retlw H'52'
			retlw H'4F'
			retlw H'4C'
			retlw H'4A'
			retlw H'47'
			retlw H'44'
			retlw H'41'
			retlw H'3F'
			retlw H'3C'
			retlw H'39'
			retlw H'37'
			retlw H'34'
			retlw H'32'
			retlw H'30'
			retlw H'2D'
			retlw H'2B'
			retlw H'29'
			retlw H'26'
			retlw H'24'
			retlw H'22'
			retlw H'20'
			retlw H'1E'
			retlw H'1C'
			retlw H'1A'
			retlw H'18'
			retlw H'17'
			retlw H'15'
			retlw H'13'
			retlw H'12'
			retlw H'10'
			retlw H'0F'
			retlw H'0E'
			retlw H'0C'
			retlw H'0B'
			retlw H'0A'
			retlw H'09'
			retlw H'08'
			retlw H'07'
			retlw H'06'
			retlw H'05'
			retlw H'05'
			retlw H'04'
			retlw H'03'
			retlw H'03'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'02'
			retlw H'03'
			retlw H'03'
			retlw H'04'
			retlw H'05'
			retlw H'05'
			retlw H'06'
			retlw H'07'
			retlw H'08'
			retlw H'09'
			retlw H'0A'
			retlw H'0B'
			retlw H'0C'
			retlw H'0E'
			retlw H'0F'
			retlw H'10'
			retlw H'12'
			retlw H'13'
			retlw H'15'
			retlw H'17'
			retlw H'18'
			retlw H'1A'
			retlw H'1C'
			retlw H'1E'
			retlw H'20'
			retlw H'22'
			retlw H'24'
			retlw H'26'
			retlw H'29'
			retlw H'2B'
			retlw H'2D'
			retlw H'30'
			retlw H'32'
			retlw H'34'
			retlw H'37'
			retlw H'39'
			retlw H'3C'
			retlw H'3F'
			retlw H'41'
			retlw H'44'
			retlw H'47'
			retlw H'4A'
			retlw H'4C'
			retlw H'4F'
			retlw H'52'
			retlw H'55'
			retlw H'58'
			retlw H'5B'
			retlw H'5E'
			retlw H'61'
			retlw H'64'
			retlw H'67'
			retlw H'6A'
			retlw H'6D'
			retlw H'70'
			retlw H'73'
			retlw H'76'
			retlw H'79'
			retlw H'7C'

			end