;**************combine 8255, keyboard and lcm control program****************
;**************provide this program to students for the second stage test****
;**************Author by 吳清祥 *******************
;---------------8255 registers define-----------------
ctrl55 equ 0x5f
pa55 equ 0x5e
pb55 equ 0x5d
pc55 equ 0x5c
pcbit equ 0x5b
;
a0_8255 equ p2.0
a1_8255 equ p2.1
;***************keyboard rigisters define**************
keynum equ 0x5a ;keynumber
keydbl equ 0x59 ;debug bounce,double check
counter equ 0x58 ;scan keyboard array
bounce0 equ 0x57
bounce1 equ 0x56
key_f equ 22h.0
;***************lcm rigisters define**************
abuf equ 0x55 ;the data write to lcm
atmp equ 0x54 ;the data read from lcm
;
;
;==============================================================================
;LCD_RS========>pc0;LCD_RW========>Pc1
;LCD_En========>pc2;LCD_BUS=======>Pa0-pa7
;data(command,address or data)==>ir(command,address) or dr(data)
;cg rom(192 words),cg ram(8*8 bytes),dd ram(80 bytes)
;first line(0) address=00h->0fh;second line(1) address->40h-4fh
;==============================================================================
org 00h
Initial:
mov ctrl55,#82h ;8255 initial status setting
call wr_ctrl ;pa:output,pb:input,pc:output
; ::::::: Initial LCD :::::::
;-------lcm function setting
mov abuf,#38h ; Set for 8 bit data transfer and
call wr_lcdcmd ; address type b,font=5*7
;-------lcm display control
mov abuf,#0eh ; Ture on the display and cursor.
call wr_lcdcmd ; cursor no twinkle
;-------lcm entry model setting
mov abuf,#06h ; Set the LCD unit to increment
call wr_lcdcmd ; the address counter.
; ; 20h store in all dd ram address
sho_main:
mov dptr,#main_scr1 ; Get the 1st row data(address)
call sho_lcm1 ; Call lcm display sub-program2
mov dptr,#main_scr2 ; Get the 2nd row data(address)
call sho_lcm2 ; Call lcm display sub-program2
;+++++++main program start++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
loop:
call scan_key
mov a,keynum
cjne a,#0ah,loop ;判斷是否為Menu鍵
;
sho_menu:
mov dptr,#menu_scr1
call sho_lcm1
mov dptr,#menu_scr2
call sho_lcm2
;---------------------------------------
loop_1:
call scan_key
mov a,keynum
cjne a,#0ah,loop_1
;
jmp sho_main
;*******lcm display data sub-program*****************************************************
sho_lcm1:
call lcd_cls ;clear display and cursor return
call lcd_printstring
ret
sho_lcm2: ;=======cursor to second line
clr a ;homing to left
setb b.0 ;Cursor to second line(1)
call lcd_locate ;b.0=0:line0,b.0=1:line1
call lcd_printstring
ret
;=======display data array====================================================
main_scr1: db "Welcome",0
main_scr2: db "9879512",0
menu_scr1: db "1.TS 2.NS ",0
menu_scr2: db "3.NI 4.Return",0
;=============================================================================
lcd_cls:
mov abuf, #01h ;Clear display
call wr_lcdcmd
ret
; ------------------------------------------------
lcd_home:
mov abuf, #02h ;Cursor home
call wr_lcdcmd
ret
; ------------------------------------------------
lcd_locate:
anl a, #00001111b ;00-0fh or 40-4fh
jnb b.0,setb7
setb acc.6 ;second address 40-4fh
setb7: setb acc.7 ;data to ddram not to cgram
mov abuf,a
call wr_lcdcmd
ret
; ------------------------------------------------
lcd_printstring:
clr a
movc a,@a+dptr
jz endps ;if a=0 is endding
mov abuf,a
call wr_lcddat
inc dptr
jmp lcd_printstring
endps: ret
; ------------------------------------------------
lcd_rdpost:
call rd_lcdcom
mov a,atmp
clr acc.7
clr b.0
jnb acc.6,notsec ;40-4fh
setb b.0
clr acc.6
notsec: ret
; ------------------------------------------------
wr_lcddat:
call chk_lcdbzy
mov pcbit,#0 ;lcd_rs=>pc0
call st_pc
mov pcbit,#1 ;lcd_rw=>pc1
call cl_pc
mov pcbit,#2 ;lcd_en=>pc2
call st_pc
mov pa55,abuf ;lcd data=>pa
call wr_pa
mov pcbit,#2 ;lcd_en=>pc2
call cl_pc
mov pcbit,#1 ;lcd_rw=>pc1
call st_pc
mov pcbit,#0 ;lcd_rs=>pc0
call cl_pc
ret
; ------------------------------------------------
wr_lcdcmd:
call chk_lcdbzy
mov pcbit,#0 ;lcd_rs=>pc0
call cl_pc ;rs=0->ir
mov pcbit,#1 ;lcd_rw=>pc1
call cl_pc ;rw=0->write
mov pcbit,#2 ;lcd_en=>pc2
call st_pc ;enable=1
mov pa55,abuf ;data to pa
call wr_pa
mov pcbit,#2 ;lcd_en=>pc2
call cl_pc
mov pcbit,#1 ;lcd_rw=>pc1
call st_pc
mov pcbit,#0 ;lcd_rs=>pc0
call st_pc
ret
; ------------------------------------------------
rd_lcdcom:
mov ctrl55,#92h ;8255 work status setting
call wr_ctrl ;pa:input,pb:input,pc:output
;
mov pcbit,#0 ;lcd_rs=>pc0
call cl_pc ;read ir
mov pcbit,#1 ;lcd_rw=>pc1
call st_pc ;read model
mov pcbit,#2 ;lcd_en=>pc2
call st_pc
call rd_pa
mov atmp,pa55
mov pcbit,#2 ;lcd_en=>pc2
call cl_pc
mov pcbit,#1 ;lcd_rw=>pc1
call st_pc
mov pcbit,#0 ;lcd_rs=>pc0
call st_pc
;
mov ctrl55,#82h ;8255 raw status setting
call wr_ctrl ;pa:output,pb:input,pc:output
ret
; ------------------------------------------------
chk_lcdbzy:
call rd_lcdcom
mov a,atmp
jb acc.7,chk_lcdbzy
ret
;=================== 82555 control sub-routine ============================
;***************write data to control register
wr_ctrl: ;ctrl register select=11
setb a0_8255
setb a1_8255
mov a,ctrl55
movx @r0,a ;wr signal
ret
;***************output data to 8255@pa
wr_pa: ;pa register select=00
clr a0_8255
clr a1_8255
mov a,pa55
movx @r0,a ;wr signal
ret
;**************input data from 8255@pa
rd_pa:
clr a0_8255 ;pa register select=00
clr a1_8255
movx a,@r0 ;rd signal
mov pa55,a
ret
;***************input data from 8255@pb
rd_pb: ;pb register select=01
setb a0_8255
clr a1_8255
movx a,@r0 ;rd signal
mov pb55,a
ret
;**************output data to 8255@pc by single-bit model
st_pc: ;pc register select=10
setb a0_8255 ;ctrl register select=11
setb a1_8255
mov a,pcbit
setb c
rlc a
movx @r0,a ;wr signal
ret
;
cl_pc:
setb a0_8255 ;ctrl register select=11
setb a1_8255
mov a,pcbit
clr c
rlc a
movx @r0,a ;wr signal
ret
;=============================================================================================
;
scan_key: mov keynum,#0 ;key counter=0
clr key_f ;initial
;
;row-0 ;74139=>q0=0
mov pcbit,#4 ;pc4=0
call cl_pc
mov pcbit,#5 ;pc5=0
call cl_pc
call rd_pb ;read pb,data store at pb55
call check_key
jbc key_f,have_state
;row-1 ;74139=>q1=0
mov pcbit,#4 ;pc4=1
call st_pc
mov pcbit,#5 ;pc5=0
call cl_pc
call rd_pb ;read pb,data store at pb55
call check_key
jbc key_f,have_state
;row-2 ;74139=>q2=0
mov pcbit,#4 ;pc4=0
call cl_pc
mov pcbit,#5 ;pc5=1
call st_pc
call rd_pb ;read pb,data store to pb55
call check_key
jbc key_f,have_state
;row-3 ;74139=>q3=0
mov pcbit,#4 ;pc4=1
call st_pc
mov pcbit,#5 ;pc5=1
call st_pc
call rd_pb ;read pb,data store to pb55
call check_key
jbc key_f,have_state
;
ret
;
have_state:
mov a,keynum
cjne a,#0ffh,is_key
is_key: ret
;***************check key whether true and count key number
check_key:
anl pb55,#0x0f ;pb0-pb3
mov a,pb55
mov counter,#4
nextk: rrc a
jnc dblchk
inc keynum
djnz counter,nextk
ret
;
dblchk: mov keydbl,pb55
mov bounce0,#200 ;about delay time=80mS
chklp: mov bounce1,#250
djnz bounce1,$
djnz bounce0,chklp
call rd_pb ;read pb,data store to pb55
anl pb55,#0x0f ;pb0-pb3
mov a,pb55
cjne a,keydbl,not_key
setb key_f ;have state
ret
not_key: setb key_f
mov keynum,#0ffh ;not key,is bounce or noise
ret
;------------------------------------------------------------------
;------------------------------------------------------------------
end
