UART、LCD與4x4鍵盤應用

	;------------------------------------------
	; ==================================
	; == uart、lcd與4x4鍵盤應用 ==
	; == 2014/12/28 ==
	; == 蘇偉諺 4a037052 ==
	; ==================================
	;------------------------------------------
	;按下按鍵後 該按鍵值會從lcd第一列最右邊慢慢移動至最左邊停止
	;-----------------------------------------------------------------------------
	; parameter define
	;-----------------------------------------------------------------------------
	lcd_rs equ p2.1
	lcd_enable equ p3.7
	lcd_bus equ p0
	keyport equ p2
	keyflag equ 20h.2
	scancode equ 33h
	keyno equ 34h;;????
	rxdflag equ 20h.3
	;-----------------------------------------------------------------------------
	; main program
	;-----------------------------------------------------------------------------
	org 00h
	mov sp,#5fh
	call initlcd
	call uartinit
	; mov r0,#15
	again: mov r0,#16
	call keyin
	jnb keyflag,again
	call txd0
	rrx: call rxd0
	jnb rxdflag,rrx;;;這邊要到呼叫rxd0的之方，否則到again的話，或沒一次接收成功，會導致多傳兩次以上 8051可以多接收一位員組資料暫存 所以會傳副接收到暫存的資料
	mov r3,a
	;--------------------------------------------
	; mov b,r0
	; mov a,#1
	; call goxy
	; mov a,r3
	; mov dptr,#str;;;;;;
	; movc a,@a+dptr
	; call wrdr
	; mov r7,#??
	; call delay
	; mov b,r0
	; mov a,#1
	; call goxy
	; mov a,#' '
	; call wrdr
	;
	; mov b,r0
	; mov a,#1
	; call goxy
	; mov a,r3
	; mov dptr,#str
	; movc a,@a+dptr
	; call wrdr
	; mov r7,#??
	; call delay
	; mov b,r0
	; mov a,#1
	; call goxy
	; mov a,#' '
	; call wrdr
	;--------------------------------------------------
	goprint: mov b,r0
	mov a,#1
	call goxy
	mov a,#' '
	call wrdr
	dec r0
	mov b,r0
	mov a,#1
	call goxy
	mov a,r3
	mov dptr,#str
	movc a,@a+dptr
	call wrdr
	mov r7,#10
	call delay50ms
	cjne r0,#0,goprint
	jmp again
	;-----------string table------------------------
	str: db '0123456789abcdef'
	;-----------------------------------------------------------------------------
	; scan keyboard
	;-----------------------------------------------------------------------------
	keyin: push 00
	push 01
	mov r0,#0
	mov scancode,#11111110b
	keyrow: mov keyport,scancode
	mov r7,#4
	call delay
	mov a,keyport
	mov r1,#4
	swap a
	kcol: rrc a
	jnc keypressed
	inc r0
	djnz r1,kcol
	mov a,scancode
	rl a
	mov scancode,a
	jnb acc.4,nokey;;;;;;;;;;;;;;;;;;;;
	jmp keyrow
	nokey: clr keyflag
	jmp keyend
	keypressed: mov a,r0
	setb keyflag
	keyend: pop 01
	pop 00
	ret
	;-----------------------------------------------------------------------------
	; go x line, y char
	;-----------------------------------------------------------------------------
	goxy: anl b,#00001111b
	cjne a,#1,chk1
	mov a,b
	add a,#10000000b;setb a.7 orl 10000000b
	call wrir
	ret
	chk1: mov a,b
	add a,#11000000b
	call wrir
	ret
	;-----------------------------------------------------------------------------
	; initial lcd
	;-----------------------------------------------------------------------------
	initlcd: mov a,#38h
	call wrir
	mov a,#0dh
	call wrir
	mov a,#06h
	call wrir
	clrlcd: mov a,#01h
	call wrir
	mov r7,#40;清除需延遲2ms
	call delay
	ret
	;-------------------------------------------------------------------------------
	; delay time=r7*0.05ms
	;-------------------------------------------------------------------------------
	delay: mov tmod,#00100001b
	dloop: mov th0,#high(65536-50)
	mov tl0,#low(65536-50)
	setb tr0
	jnb tf0,$
	clr tr0
	clr tf0
	djnz r7,dloop
	ret
	;-------------------------------------------------------------------------------
	; delay time=r7*50ms
	;-------------------------------------------------------------------------------
	delay50ms:
	dloop1: mov th0,#high(65536-50000)
	mov tl0,#low(65536-50000)
	setb tr0
	jnb tf0,$
	clr tr0
	clr tf0
	djnz r7,dloop1
	ret
	;-----------------------------------------------------------------------------
	; write control word to instruction register
	;-----------------------------------------------------------------------------
	wrir: setb lcd_enable
	clr lcd_rs
	mov lcd_bus,a
	clr lcd_enable
	mov r7,#1
	call delay
	ret
	;-----------------------------------------------------------------------------
	; write data to data register
	;-----------------------------------------------------------------------------
	wrdr: setb lcd_enable
	setb lcd_rs
	mov lcd_bus,a
	clr lcd_enable
	mov r7,#1
	call delay
	ret
	rxd0: jnb ri,rxdret
	mov a,sbuf
	clr ri
	setb rxdflag
	ret
	rxdret: clr rxdflag
	ret
	txd0: clr ti
	mov sbuf,a
	jnb ti,$
	clr ti
	ret
	;------------------------------------------------------------------------------
	; initial uart,timer1,timer0
	;12mhz: timer1,th1
	;-----------------------------------------------------------------------------
	uartinit: mov scon,#01010000b ;uart:mode 1
	mov tmod,#00100001b ;timer1:mode 2, timer0:mode 1
	mov pcon,#10000000b ;(smod=1)
	mov th1,#255 ;baud rate=62500 bits/sec
	setb tr1 ;start timer1
	; clr tr0
	; clr tf0
	clr ri
	clr ti
	ret
	end

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