Automatic Temprature Report

PROJECT REPORT
ON
AUTOMATIC TEMPRATURE CONTROLLER
BY
CETPA INFOTECH PRIVATE LIMITED
CONTENTS
1. 8051 Microcontroller Architecture
2. Variant in Atmel 8051 Microcontrollers
3. Features o AT8!c51" AT8!c52 an# AT8!s51
$. Features o %C& 'se#
5. &S1(21 an# its Features
(. )C* %a+out
,. Source Co#e in Assem-l+
8. Com.onent %ist.
!. A..en#i/
10. *i-lio0ra.h+
8051 Microcontrollr
AT8!C511
T! AT8"C51 i# $ lo%&'o%r( !i)!&'r*or+$nc CMO, 8&-it +icroco+'.tr %it! /0
-1t# o* Fl$#! 'ro)r$++$-l $n2 r$#$-l r$2 onl1 ++or1 3PEROM45 T! 26ic
i# +$n.*$ct.r2 .#in) At+l7# !i)!&2n#it1 non6ol$til ++or1 tc!nolo)1 $n2 i#
co+'$ti-l %it! t! in2.#tr1&#t$n2$r2 MC,&51 in#tr.ction #t $n2 'ino.t5 T! on&c!i'
Fl$#! $llo%# t! 'ro)r$+ ++or1 to - r'ro)r$++2 in&#1#t+ or -1 $ con6ntion$l
non6ol$til ++or1 'ro)r$++r5 B1 co+-inin) $ 6r#$til 8&-it CPU %it! Fl$#!
on $ +onolit!ic c!i'( t! At+l AT8"C51 i# $ 'o%r*.l +icroco+'.tr %!ic! 'ro6i2#
$ !i)!l1&*l8i-l $n2 co#t&**cti6 #ol.tion to +$n1 +-222 control $''lic$tion#5
)in Coni0urtion
T! AT8"C51 'ro6i2# t! *ollo%in) #t$n2$r2 *$t.r#9 /0 -1t# o* Fl$#!( 1:8 -1t# o*
RAM( ;: I<O lin#( t%o 1=&-it ti+r<co.ntr#( $ *i6 6ctor t%o&l6l intrr.'t
$rc!itct.r( $ *.ll 2.'l8 #ri$l 'ort( on&c!i' o#cill$tor $n2 cloc> circ.itr15 In $22ition(
t! AT8"C51 i# 2#i)n2 %it! #t$tic lo)ic *or o'r$tion 2o%n to ?ro *[email protected] $n2
#.''ort# t%o #o*t%$r #lct$-l 'o%r #$6in) +o2#5 T! I2l Mo2 #to'# t! CPU
%!il $llo%in) t! RAM( ti+r<co.ntr#( #ri$l 'ort $n2 intrr.'t #1#t+ to contin.
*.nctionin)5 T! Po%r&2o%n Mo2 #$6# t! RAM contnt# -.t *r?# t! o#cill$tor
2i#$-lin) $ll ot!r c!i' *.nction# .ntil t! n8t !$r2%$r r#t5
Pin Description
VCC
,.''l1 6olt$)5
GND
Aro.n25
Port 0
Port 0 i# $n 8&-it o'n&2r$in -i&2irction$l I<O 'ort5 A# $n o.t'.t 'ort( $c! 'in c$n #in>
i)!t TTL in'.t#5 B!n 1# $r %rittn to 'ort 0 'in#( t! 'in# c$n - .#2 $# !i)!
i+'2$nc in'.t#5 Port 0 +$1 $l#o - con*i).r2 to - t! +.lti'l82 lo% or2r
A22r## <2$t$ -.# 2.rin) $cc### to 8trn$l 'ro)r$+ $n2 2$t$ ++or15 In t!i# +o2 P0
!$# intrn$l '.ll .'#5 Port 0 $l#o rci6# t! co2 -1t# 2.rin) Fl$#! 'ro)r$++in)(
$n2 o.t'.t# t! co2 -1t# 2.rin) 'ro)r$+ 6ri*ic$tion5 E8trn$l '.ll .'# $r [email protected]
2.rin) 'ro)r$+ 6ri*ic$tion5
Port 1
Port 1 i# $n 8&-it -i&2irction$l I<O 'ort %it! intrn$l '.ll.'#5 T! Port 1 o.t'.t -.**r#
c$n #in><#o.rc *o.r TTL in'.t#5 B!n 1# $r %rittn to Port 1 'in# t!1 $r '.ll2 !i)!
-1 t! intrn$l '.ll.'# $n2 c$n - .#2 $# in'.t#5 A# in'.t#( Port 1 'in# t!$t $r 8trn$ll1
-in) '.ll2 lo% %ill #o.rc c.rrnt 3IIL4 -c$.# o* t! intrn$l '.ll.'#5 Port 1 $l#o
rci6# t! lo%&or2r $22r## -1t# 2.rin) Fl$#! 'ro)r$++in) $n2 6ri*ic$tion5
Port 2
Port : i# $n 8&-it -i&2irction$l I<O 'ort %it! intrn$l '.ll.'#5 T! Port : o.t'.t -.**r#
c$n #in><#o.rc *o.r TTL in'.t#5 B!n 1# $r %rittn to Port : 'in# t!1 $r '.ll2 !i)!
-1 t! intrn$l '.ll.'# $n2 c$n - .#2 $# in'.t#5 A# in'.t#( Port : 'in# t!$t $r 8trn$ll1
-in) '.ll2 lo% %ill #o.rc c.rrnt 3IIL4 -c$.# o* t! intrn$l '.ll.'#5 Port : +it# t!
!i)!&or2r $22r## -1t 2.rin) *tc!# *ro+ 8trn$l 'ro)r$+ ++or1 $n2 2.rin)
$cc### to 8trn$l 2$t$ ++or1 t!$t .# 1=&-it $22r### 3MOVC D DPTR45 In t!i#
$''lic$tion( it .## #tron) intrn$l '.ll&.'# %!n +ittin) 1#5 D.rin) $cc### to 8trn$l
2$t$ ++or1 t!$t .# 8&-it $22r### 3MOVC D RI4( Port : +it# t! contnt# o* t! P:
,'ci$l F.nction R)i#tr5 Port : $l#o rci6# t! !i)!&or2r $22r## -it# $n2 #o+
control #i)n$l# 2.rin) Fl$#! 'ro)r$++in) $n2 6ri*ic$tion5
Port 3
Port ; i# $n 8&-it -i&2irction$l I<O 'ort %it! intrn$l '.ll.'#5 T! Port ; o.t'.t -.**r#
c$n #in><#o.rc *o.r TTL in'.t#5 B!n 1# $r %rittn to Port ; 'in# t!1 $r '.ll2 !i)!
-1 t! intrn$l '.ll.'# $n2 c$n - .#2 $# in'.t#5 A# in'.t#( Port ; 'in# t!$t $r 8trn$ll1
-in) '.ll2 lo% %ill #o.rc c.rrnt 3IIL4 -c$.# o* t! '.ll.'#5 Port ; $l#o #r6# t!
*.nction# o* 6$rio.# #'ci$l *$t.r# o* t! AT8"C51 $# li#t2 -lo%9 Port ; $l#o rci6#
#o+ control #i)n$l# *or Fl$#! 'ro)r$++in) $n2 6ri*ic$tion5
RST
R#t in'.t5 A !i)! on t!i# 'in *or t%o +$c!in c1cl# %!il t! o#cill$tor i# r.nnin)
r#t# t! 26ic.
ALE/PROG
A22r## L$tc! En$-l o.t'.t '.l# *or l$tc!in) t! lo% -1t o* t! $22r## 2.rin)
$cc### to 8trn$l ++or15 T!i# 'in i# $l#o t! 'ro)r$+ '.l# in'.t 3PROA4 2.rin)
Fl$#! 'ro)r$++in)5 In nor+$l o'r$tion ALE i# +itt2 $t $ con#t$nt r$t o* 1<= t!
o#cill$tor *[email protected]( $n2 +$1 - .#2 *or 8trn$l ti+in) or cloc>in) '.r'o##5 Not(
!o%6r( t!$t on ALE
'.l# i# #>i''2 2.rin) $c! $cc## to 8trn$l D$t$ M+or15 I* 2#ir2( ALE o'r$tion
c$n - 2i#$-l2 -1 #ttin) -it 0 o* ,FR loc$tion 8EH5 Bit! t! -it #t( ALE i# $cti6 onl1
2.rin) $ MOVC or MOVC in#tr.ction5 Ot!r%i#( t! 'in i# %$>l1 '.ll2 !i)!5 ,ttin)
t! ALE&2i#$-l -it !$# no**ct i* t! +icrocontrollr i# in 8trn$l 8c.tion +o2.
PSEN
Pro)r$+ ,tor En$-l i# t! r$2 #tro- to 8trn$l 'ro)r$+ ++or15 B!n t! AT8"C51
i# 8c.tin) co2 *ro+ 8trn$l 'ro)r$+ ++or1( P,EN i# $cti6$t2 t%ic $c! +$c!in
c1cl( 8c't t!$t t%o P,EN $cti6$tion# $r #>i''2 2.rin) $c! $cc## to 8trn$l 2$t$
++or15
EA/VPP
E8trn$l Acc## En$-l5 EA +.#t - #tr$''2 to AND in or2r to n$-l t! 26ic to
*tc! co2 *ro+ 8trn$l 'ro)r$+ ++or1 loc$tion# #t$rtin) $t 0000H .' to FFFFH5
Not( !o%6r( t!$t i* loc> -it 1 i# 'ro)r$++2( EA %ill - intrn$ll1 l$tc!2 on r#t5
EA #!o.l2 - #tr$''2 to VCC *or intrn$l 'ro)r$+ 8c.tion#5 T!i# 'in $l#o rci6# t!
1:&6olt 'ro)r$++in) n$-l 6olt$) 3VPP4 2.rin) Fl$#! 'ro)r$++in)( *or '$rt# t!$t
[email protected] 1:&6olt VPP5
XTAL1
In'.t to t! in6rtin) o#cill$tor $+'li*ir $n2 in'.t to t! intrn$l cloc> o'r$tin) circ.it5
XTAL2
O.t'.t *ro+ t! in6rtin) o#cill$tor $+'li*ir5
Oscillator Caracters!
CTAL1 $n2 CTAL: $r t! in'.t $n2 o.t'.t( r#'cti6l1( o* $n in6rtin) $+'li*ir
%!ic! c$n - con*i).r2 *or .# $# $n on&c!i' o#cill$tor( $# #!o%n in Fi).r 15 Eit!r $
@.$rt? cr1#t$l or cr$+ic r#on$tor +$1 - .#25 To 2ri6 t! 26ic *ro+ $n 8trn$l
cloc> #o.rc( CTAL: #!o.l2 - l*t .nconnct2 %!il CTAL1 i# 2ri6n $# #!o%n in
Fi).r :5 T!r $r no [email protected]+nt# on t! 2.t1 c1cl o* t! 8trn$l cloc> #i)n$l( #inc
t! in'.t to t! intrn$l cloc>in) circ.itr1 i# t!ro.)! $ 2i6i2&-1&t%o *li'&*lo'( -.t
+ini+.+ $n2 +$8i+.+ 6olt$) !i)! $n2 lo% ti+ #'ci*ic$tion# +.#t - o-#r625
"#le $o#e
In i2l +o2( t! CPU '.t# it#l* to #l' %!il $ll t! onc!i' 'ri'!r$l# r+$in $cti65
T! +o2 i# in6o>2 -1 #o*t%$r5 T! contnt o* t! on&c!i' RAM $n2 $ll t! #'ci$l
*.nction# r)i#tr# r+$in .nc!$n)2 2.rin) t!i# +o25 T! i2l +o2 c$n - tr+in$t2
-1 $n1 n$-l2intrr.'t or -1 $ !$r2%$r r#t5 It #!o.l2 - not2 t!$t %!n i2l i#
tr+in$t2 -1 $ !$r2 %$r r#t( t! 26ic nor+$ll1 r#.+# 'ro)r$+ 8c.tion( *ro+
%!r it l*t o**( .' to t%o +$c!in c1cl# -*or t! intrn$l r#t $l)orit!+ t$>#
control5 On&c!i' !$r2%$r in!i-it# $cc## to intrn$l RAM in t!i# 6nt( -.t $cc## to t!
'ort 'in# i# not in!i-it25 To li+in$t t! 'o##i-ilit1 o* $n .n8'ct2 %rit to $ 'ort 'in
%!n I2l i# tr+in$t2 -1 r#t( t! in#tr.ction *ollo%in) t! on t!$t in6o># I2l
#!o.l2 not - on t!$t %rit# to $ 'ort 'in or to 8trn$l ++or15
Pro%ra&&in% te 'las
T! AT8"C51 i# nor+$ll1 #!i''2 %it! t! on&c!i' Fl$#! ++or1 $rr$1 in t! r$#2
#t$t 3t!$t i#( contnt# E FFH4 $n2 r$21 to - 'ro)r$++25 T! 'ro)r$++in) intr*$c
$cc't# it!r $ !i)!&6olt$) 31:&6olt4 or $ lo%&6olt$) 3VCC4 'ro)r$+ n$-l #i)n$l5
T! lo%&6olt$) 'ro)r$++in) +o2 'ro6i2# $ con6nint %$1 to 'ro)r$+ t!
AT8"C51 in#i2 t! .#r7# #1#t+( %!il t! !i)!&6olt$) 'ro)r$++in) +o2 i#
co+'$ti-l %it! con6ntion$l t!ir2 '$rt1 Fl$#! or EPROM 'ro)r$++r#5 T! AT8"C51
i# #!i''2 %it! it!r t! !i)!&6olt$) or lo%&6olt$) 'ro)r$++in) +o2 n$-l25
T! AT8"C51 co2 ++or1 $rr$1 i# 'ro)r$++2 -1t&-1-1t in it!r 'ro)r$++in)
+o25 To 'ro)r$+ $n1 non-l$n> -1t in t! on&c!i' Fl$#! M+or1( t! ntir ++or1
+.#t - r$#2 .#in) t! C!i' Er$# Mo25
Pro%ra&&in% Al%orit&!
B*or 'ro)r$++in) t! AT8"C51( t! $22r##( 2$t$ $n2 control #i)n$l# #!o.l2 - #t .'
$ccor2in) to t! Fl$#! 'ro)r$++in) +o2 t$-l5 To 'ro)r$+ t! AT8"C51( t$> t!
*ollo%in) #t'#5
15 In'.t t! 2#ir2 ++or1 loc$tion on t! $22r## lin#5
:5 In'.t t! $''ro'ri$t 2$t$ -1t on t! 2$t$ lin#5
;5 Acti6$t t! corrct co+-in$tion o* control #i)n$l#5
/5 R$i# EA<VPP to 1:V *or t! !i)!&6olt$) 'ro)r$++in) +o25
55 P.l# ALE<PROA onc to 'ro)r$+ $ -1t in t! Fl$#! $rr$1 or t! loc> -it#5 T! -1t&
%rit c1cl i# #l*&ti+2 $n2 t1'ic$ll1 t$># no +or t!$n 155 +#5
R'$t #t'# 1 t!ro.)! 5( c!$n)in) t! $22r## $n2 2$t$ *or t! ntir $rr$1 or .ntil t!
n2 o* t! o-Fct *il i# r$c!25
Data Pollin%! T! AT8"C51 *$t.r# D$t$ Pollin) to in2ic$t t! n2 o* $ %rit c1cl5
D.rin) $ %rit c1cl( $n $tt+'t2 r$2 o* t! l$#t -1t %rittn %ill r#.lt in t!
co+'l+nt o* t! %rittn 2$t.+ on PO5G5 Onc t! %rit c1cl !$# -n co+'lt2( tr.
2$t$ $r 6$li2 on $ll o.t'.t#( $n2 t! n8t c1cl +$1 -)in5 D$t$ Pollin) +$1 -)in $n1
ti+ $*tr $ %rit c1cl !$# -n initi$t25
Rea#(/)*s(! T! 'ro)r## o* -1t 'ro)r$++in) c$n $l#o - +onitor2 -1 t! RDY<B,Y
o.t'.t #i)n$l5 P;5/ i# '.ll2 lo% $*tr ALE )o# !i)! 2.rin) 'ro)r$++in) to in2ic$t
BU,Y5 P;5/ i# '.ll2 !i)! $)$in %!n 'ro)r$++in) i# 2on to in2ic$t READY5
Pro%ra& Veri+(9 I* loc> -it# LB1 $n2 LB: !$6 not -n 'ro)r$++2( t! 'ro)r$++2
co2 2$t$ c$n - r$2 -$c> 6i$ t! $22r## $n2 2$t$ lin# *or 6ri*ic$tion5 T! loc> -it#
c$nnot - 6ri*i2 2irctl15 Vri*ic$tion o* t! loc> -it# i# $c!i62 -1 o-#r6in) t!$t t!ir
*$t.r# $r n$-l25
Cip Erase9 T! ntir Fl$#! $rr$1 i# r$#2 lctric$ll1 -1 .#in) t! 'ro'r co+-in$tion
o* control #i)n$l# $n2 -1 !ol2in) ALE<PROA lo% *or 10 +#5 T! co2 $rr$1 i# %rittn
%it! $ll H1I#5 T! c!i' r$# o'r$tion +.#t - 8c.t2 -*or t! co2 ++or1 c$n -
r&'ro)r$++25
Rea#in% te Si%nat*re )(tes! T! #i)n$t.r -1t# $r r$2 -1 t! #$+ 'roc2.r $# $
nor+$l 6ri*ic$tion o* loc$tion# 0;0H( 0;1H( $n2 0;:H( 8c't t!$t P;5= $n2 P;5G +.#t
- '.ll2 to $ lo)ic lo%5 T! 6$l.# rt.rn2 $r $# *ollo%#5
30;0H4 E 1EH in2ic$t# +$n.*$ct.r2 -1 At+l
30;1H4 E 51H in2ic$t# 8"C51
30;:H4 E FFH in2ic$t# 1:V 'ro)r$++in)
30;:H4 E 05H in2ic$t# 5V 'ro)r$++in)
)ro0rammin0 the AT8!C51
AT8"C5:9
Features
2 Com.ati-le 3ith MCS4515 )ro#ucts
2 86 *+tes o 7n4S+stem 8e.ro0ramma-le Flash Memor+
2 En#urance1 1"000 9rite:Erase C+cles
2 Full+ Static O.eration1 0 ;< to 2$ M;<
2 Three4le=el )ro0ram Memor+ %oc>
2 25( / 84-it 7nternal 8AM
2 32 )ro0ramma-le 7:O %ines
2 Three 1(4-it Timer:Counters
2 Ei0ht 7nterru.t Sources
2 )ro0ramma-le Serial Channel
2 %o34.o3er 7#le an# )o3er4#o3n Mo#es
Description
T! AT8"C5: i# $ lo%&'o%r( !i)!&'r*or+$nc CMO, 8&-it +icroco+'.tr %it! 80
-1t# o* Fl$#! 'ro)r$++$-l $n2 r$#$-l r$2 onl1 ++or1 3PEROM45 T! 26ic i#
+$n.*$ct.r2 .#in) At+l7# !i)!&2n#it1 non6ol$til ++or1 tc!nolo)1 $n2 i#
co+'$ti-l %it! t! in2.#tr1&#t$n2$r2 80C51 $n2 80C5: in#tr.ction #t $n2 'in o.t5 T!
on&c!i' Fl$#! $llo%# t! 'ro)r$+ ++or1 to - r'ro)r$++2 in&#1#t+ or -1 $
con6ntion$l non6ol$til ++or1 'ro)r$++r5 B1 co+-inin) $ 6r#$til 8&-it CPU %it!
Fl$#! on $ +onolit!ic c!i'( t! At+l AT8"C5: i# $ 'o%r*.l +icroco+'.tr %!ic!
'ro6i2# $ !i)!l1&*l8i-l $n2 co#t&**cti6 #ol.tion to +$n1 +-222 control
$''lic$tion#5
Pin Dia%ra&!
Te AT,-C.2 pro/i#es te +ollo0in% stan#ar# +eat*res!
80 -1t# o* Fl$#!( :5= -1t# o* RAM( ;: I<O lin#( t!r 1=&-it ti+r<co.ntr#( $ #i8&
6ctor t%o&l6l intrr.'t $rc!itct.r( $ *.ll&2.'l8 #ri$l 'ort( on&c!i' o#cill$tor( $n2
cloc> circ.itr15 In $22ition( t! AT8"C5: i# 2#i)n2 %it! #t$tic lo)ic *or o'r$tion 2o%n
to ?ro *[email protected] $n2 #.''ort# t%o #o*t%$r #lct$-l 'o%r #$6in) +o2#5 T! I2l
Mo2 #to'# t! CPU %!il $llo%in) t! RAM( ti+r<co.ntr#( #ri$l 'ort( $n2 intrr.'t
#1#t+ to contin. *.nctionin)5 T! Po%r&2o%n +o2 #$6# t! RAM contnt# -.t
*r?# t! o#cill$tor( 2i#$-lin) $ll ot!r c!i' *.nction# .ntil t! n8t !$r2%$r r#t5
Special '*nction Re%isters
A +$' o* t! on&c!i' ++or1 $r$ c$ll2 t! ,'ci$l F.nction R)i#tr 3,FR4 #'$c5
Not t!$t not $ll o* t! $22r### $r occ.'i2( $n2 .nocc.'i2 $22r### +$1 not -
i+'l+nt2 on t! c!i'5 R$2 $cc### to t!# $22r### %ill in )nr$l rt.rn r$n2o+
2$t$( $n2 %rit $cc### %ill !$6 $n in2tr+in$t **ct5 U#r #o*t%$r #!o.l2 not %rit
1# to t!# .nli#t2 loc$tion#( #inc t!1 +$1 - .#2 in *.t.r 'ro2.ct# to in6o>5
Data $e&or(
T! AT8"C5: i+'l+nt# :5= -1t# o* on&c!i' RAM5 T! .''r 1:8 -1t# occ.'1 $
'$r$lll $22r## #'$c to t! ,'ci$l F.nction R)i#tr#5 T!$t +$n# t! .''r 1:8 -1t#
!$6 t! #$+ $22r### $# t! ,FR #'$c -.t $r '!1#ic$ll1 #'$r$t *ro+ ,FR #'$c5
B!n $n in#tr.ction $cc### $n intrn$l loc$tion $-o6 $22r## GFH( t! $22r## +o2
.#2 in t! in#tr.ction #'ci*i# %!t!r t! CPU $cc### t! .''r 1:8 -1t# o* RAM
or t! ,FR #'$c5 In#tr.ction# t!$t .# 2irct $22r##in) $cc## ,FR #'$c5 n% *$t.r#5
In t!$t c$#( t! r#t or in$cti6 6$l.# o* t! n% -it# %ill $l%$1# - 05
Ti&er 2 Re%isters
Control $n2 #t$t.# -it# $r cont$in2 in r)i#tr# T:CON $n2 *or Ti+r :5 T! r)i#tr
'$ir 3RCAP:H( RCAP:L4 $r t! C$'t.r<Rlo$2 r)i#tr# *or Ti+r : in 1=&-it c$'t.r
+o2 or 1=&-it $.to&rlo$2 +o25
"nterr*pt Re%isters
T! in2i6i2.$l intrr.'t n$-l -it# $r in t! IE r)i#tr5 T%o 'rioriti# c$n - #t *or
$c! o* t! #i8 intrr.'t #o.rc# in t! IP r)i#tr5r5 #'ci*i# %!t!r t! CPU $cc###
t! .''r 1:8 -1t# o* RAM or t! ,FR #'$c5 In#tr.ction# t!$t .# 2irct $22r##in)
$cc## ,FR #'$c5 For 8$+'l( t! *ollo%in) 2irct $22r##in) in#tr.ction $cc### t!
,FR $t loc$tion 0A0H 3%!ic! i# P:45 In#tr.ction# t!$t .# in2irct $22r##in) $cc## t!
.''r 1:8 -1t# o* RAM5 For 8$+'l( t! *ollo%in) in2irct $22r##in) in#tr.ction(
%!r R0 cont$in# 0A0H( $cc### t! 2$t$ -1t $t $22r## 0A0H( r$t!r t!$n P: 3%!o#
$22r## i# 0A0H45
MOV DR0( J2$t$
Not t!$t #t$c> o'r$tion# $r 8$+'l# o* in2irct $22r##in)( #o t! .''r 1:8 -1t# o*
2$t$ RAM $r $6$il$-l $# #t$c> #'$c5
Ti&er 0 an# 1
Ti+r 0 $n2 Ti+r 1 in t! AT8"C5: o'r$t t! #$+ %$1 $# Ti+r 0 $n2 Ti+r 1 in t!
AT8"C515
Ti&er 2
Ti+r : i# $ 1=&-it Ti+r<Co.ntr t!$t c$n o'r$t $# it!r $ ti+r or $n 6nt co.ntr5
T! t1' o* o'r$tion i# #lct2 -1 -it C<T: in t! ,FR T:CON5 Ti+r : !$# t!r
o'r$tin) +o2#9 c$'t.r( $.to&rlo$2 3.' or 2o%n co.ntin)4( $n2 -$.2 r$t )nr$tor5
T! +o2# $r #lct2 -1 -it# in T:CON5 Ti+r : con#i#t# o* t%o 8&-it r)i#tr#( TH:
$n2 TL:5 In t! Ti+r *.nction( t! TL: r)i#tr i# incr+nt2 6r1 +$c!in c1cl5
,inc $ +$c!in c1cl con#i#t# o* 1: o#cill$tor 'rio2#( t! co.nt r$t i# 1<1: o* t!
o#cill$tor *[email protected] In t! Co.ntr *.nction( t! r)i#tr i# incr+nt2 in r#'on# to $
1&to&0 tr$n#ition $t it# corr#'on2in) 8trn$l in'.t 'in( T:5 In t!i# *.nction( t! 8trn$l
in'.t i# #$+'l2 2.rin) ,5P: o* 6r1 +$c!in c1cl5 B!n t! #$+'l# #!o% $ !i)! in
on c1cl $n2 $ lo% in t! n8t c1cl( t! co.nt i# incr+nt25 T! n% co.nt 6$l.
$''$r# in t! r)i#tr 2.rin) ,;P1 o* t! c1cl *ollo%in) t! on in %!ic! t! tr$n#ition
%$# 2tct25 ,inc t%o +$c!in c1cl# 3:/ o#cill$tor 'rio2#4 $r [email protected] to rco)ni? $
1&to&0 tr$n#ition( t! +$8i+.+ co.nt r$t i# 1<:/ o* t! o#cill$tor *[email protected] To n#.r
t!$t $ )i6n l6l i# #$+'l2 $t l$#t onc -*or it c!$n)#( t! l6l #!o.l2 - !l2 *or
$t l$#t on *.ll +$c!in c1cl5
Capt*re $o#e
In t! c$'t.r +o2( t%o o'tion# $r #lct2 -1 -it ECEN: in T:CON5 I* ECEN: E 0(
Ti+r : i# $ 1=&-it ti+r or co.ntr %!ic! .'on o6r*lo% #t# -it TF: in T:CON5 T!i# -it
c$n t!n - .#2 to )nr$t $n intrr.'t5 I* ECEN: E 1( Ti+r : 'r*or+# t! #$+
o'r$tion( -.t $ 1& to&0 tr$n#ition $t 8trn$l in'.t T:EC $l#o c$.## t! c.rrnt 6$l. in
TH: $n2 TL: to - c$'t.r2 into CAP:H $n2 RCAP:L( r#'cti6l15 In $22ition( t!
tr$n#ition $t T:EC c$.## -it ECF: in T:CON to - #t5 T! ECF: -it( li> TF:( c$n
)nr$t $n intrr.'t5
A*to1reloa# 23p or Do0n Co*nter4
Ti+r : c$n - 'ro)r$++2 to co.nt .' or 2o%n %!n con*i).r2 in it# 1=&-it $.to&
rlo$2 +o25 T!i# *$t.r i# in6o>2 -1 t! DCEN 3Do%n Co.ntr En$-l4 -it loc$t2 in
t! ,FR T:MOD5 U'on r#t( t! DCEN -it i# #t to 0 #o t!$t ti+r : %ill 2*$.lt to
co.nt .'5 B!n DCEN i# #t( Ti+r : c$n co.nt .' or 2o%n( 2'n2in) on t! 6$l. o*
t! T:EC 'in5
"nterr*pts
T! AT8"C5: !$# $ tot$l o* #i8 intrr.'t 6ctor#9 t%o 8trn$l intrr.'t# 3INT0 $n2
INT14( t!r ti+r intrr.'t# 3Ti+r# 0( 1( $n2 :4( $n2 t! #ri$l 'ort intrr.'t5 E$c! o*
t!# intrr.'t #o.rc# c$n - in2i6i2.$ll1 n$-l2 or 2i#$-l2 -1 #ttin) or cl$rin) $ -it
in ,'ci$l F.nction R)i#tr IE5 IE $l#o cont$in# $ )lo-$l 2i#$-l -it( EA( %!ic! 2i#$-l#
$ll intrr.'t# $t onc5 Not t!$t -it 'o#ition IE5= i# .ni+'l+nt25 In t! AT8"C51( -it
'o#ition IE55 i# $l#o .ni+'l+nt25 U#r #o*t%$r #!o.l2 not %rit 1# to t!# -it
'o#ition#( #inc t!1 +$1 - .#2 in *.t.r AT8" 'ro2.ct#5 Ti+r : intrr.'t i# )nr$t2
-1 t! lo)ic$l OR o* -it# TF: $n2 ECF: in r)i#tr T:CON5 Nit!r o* t!# *l$)# i#
cl$r2 -1 !$r2%$r %!n t! #r6ic ro.tin i# 6ctor2 to5 In *$ct( t! #r6ic ro.tin
+$1 !$6 to 2tr+in %!t!r it %$# TF: or ECF: t!$t )nr$t2 t! intrr.'t( $n2 t!$t
-it %ill !$6 to - cl$r2 in #o*t%$r5 T! Ti+r 0 $n2 Ti+r 1 *l$)#( TF0 $n2 TF1( $r
#t $t ,5P: o* t! c1cl in %!ic! t! ti+r# o6r*lo%5 T! 6$l.# $r t!n 'oll2 -1 t!
circ.itr1 in t! n8t c1cl5 Ho%6r( t! Ti+r : *l$)( TF:( i# #t $t ,:P: $n2 i# 'oll2 in
t! #$+ c1cl in %!ic! t! ti+r o6r*lo%#5
AT,-S.1!
T! AT8"L,51 i# $ lo%&6olt$)( !i)!&'r*or+$nc CMO, 8&-it +icrocontrollr %it! /0
-1t# o* in&#1#t+ 'ro)r$++$-l Fl$#! ++or15 T! 26ic i# +$n.*$ct.r2 .#in)
At+l7# !i)!&2n#it1 non6ol$til ++or1 tc!nolo)1 $n2 i# co+'$ti-l %it! t!
in2.#tr1&#t$n2$r2 80C51 in#tr.ction #t $n2 'in o.t5 T! on&c!i' Fl$#! $llo%# t!
'ro)r$+ ++or1 to - r'ro)r$++2 in&#1#t+ or -1 $ con6ntion$l non6ol$til
++or1 'ro)r$++r5 B1 co+-inin) $ 6r#$til 8&-it CPU %it! in&#1#t+ 'ro)r$++$-l
Fl$#! on $ +onolit!ic c!i'( t! At+l AT8"L,51 i# $ 'o%r*.l +icrocontrollr %!ic!
'ro6i2# $ !i)!l1&*l8i-l $n2 co#t&**cti6 #ol.tion to +$n1 +-222 control
$''lic$tion#5 T! AT8"L,51 'ro6i2# t! *ollo%in) #t$n2$r2 *$t.r#9 /0 -1t# o* Fl$#!(
1:8 -1t# o* RAM( ;: I<O lin#( B$tc!2o) ti+r( t%o 2$t$ 'ointr#( t%o 1=&-it
ti+r<co.ntr#( $ *i6&6ctor t%o&l6l intrr.'t $rc!itct.r( $ *.ll 2.'l8 #ri$l 'ort( on&
c!i' o#cill$tor( $n2 cloc> circ.itr15 In $22ition( t! AT8"L,51 i# 2#i)n2 %it! #t$tic
lo)ic *or o'r$tion 2o%n to ?ro *[email protected] $n2 #.''ort# t%o #o*t%$r #lct$-l 'o%r
#$6in) +o2#5 T! I2l Mo2 #to'# t! CPU %!il $llo%in) t! RAM( ti+r<co.ntr#(
#ri$l 'ort( $n2 intrr.'t #1#t+ to contin. *.nctionin)5 T! Po%r&2o%n +o2 #$6#
t! RAM contnt# -.t *r?# t! o#cill$tor( 2i#$-lin) $ll ot!r c!i' *.nction# .ntil t!
n8t 8trn$l intrr.'t or !$r2%$r r#t5 R#t $ll *.nction o* t!i# At+l ,ri#
Microcontrollr i# #$+ $# it# ot!r ++-r#5
Architecture Features:
• ,1)it CP3 Opti&i5e# +or Control Applications
• E6tensi/e )oolean Processin% Capa7ilities 2Sin%le1)it Lo%ic4
• On1Cip 'las Pro%ra& $e&or(
• On1Cip Data RA$
• )i#irectional an# "n#i/i#*all( A##ressa7le "/O Lines
• $*ltiple 181)it Ti&er/Co*nters
• '*ll D*ple6 3ART
• $*ltiple So*rce/Vector/Priorit( "nterr*pt Str*ct*re
• On1Cip Cloc9 Oscillator
• On1cip EEPRO$ 2AT,-S series4
• SP" Serial )*s "nter+ace 2AT,-S Series4
• :atc#o% Ti&er 2AT,-S Series4
$e&or( Or%ani5ation
Lo%ical Separation o+ Pro%ra& Data $e&or(
All At+l Fl$#! +icrocontrollr# !$6 #'$r$t $22r## #'$c# *or 'ro)r$+ $n2 2$t$
++or15 T! lo)ic$l #'$r$tion o* 'ro)r$+ $n2 2$t$ ++or1 $llo%# t! 2$t$ ++or1 to
- $cc##2 -1 8&-it $22r###( %!ic! c$n - +or @.ic>l1 #tor2 $n2 +$ni'.l$t2 -1 $n
8& -it CPU5 N6rt!l##( 1=&-it 2$t$ ++or1 $22r### c$n $l#o - )nr$t2 t!ro.)!
t! DPTR r)i#tr5 Pro)r$+ ++or1 c$n onl1 - r$25 T!r c$n - .' to =/0 -1t# o*
2irctl1 $22r##$-l 'ro)r$+ ++or15 T! r$2 #tro- *or 8trn$l 'ro)r$+ ++or1 i#
t! Pro)r$+ ,tor En$-l #i)n$l 3P,EN45 D$t$ ++or1 occ.'i# $ #'$r$t $22r## #'$c
*ro+ 'ro)r$+ ++or15 U' to =/0 -1t# o* 8trn$l ++or1 c$n - 2irctl1 $22r##2 in
t! 8trn$l 2$t$ ++or1 #'$c5 T! CPU )nr$t# r$2 $n2 %rit #i)n$l#( RD $n2 BR(
2.rin) 8trn$l 2$t$ ++or1 $cc###5 E8trn$l 'ro)r$+ ++or1 $n2 8trn$l 2$t$
++or1 c$n - co+-in2 -1 $''l1in) t! RD $n2 P,EN #i)n$l# to t! in'.t o* $n AND
)$t $n2 .#in) t! o.t'.t o* t! )$t $# t! r$2 #tro- to t! 8trn$l 'ro)r$+<2$t$
++or15
Pro%ra& $e&or(
A*tr r#t( t! CPU -)in# 8c.tion *ro+ loc$tion 0000H5 $c! intrr.'t i# $##i)n2 $
*i82loc$tion in 'ro)r$+ ++or15 T! intrr.'t c$.## t! CPU to F.+' to t!$t loc$tion(
%!r it 8c.t# t! #r6ic ro.tin5 E8trn$l Intrr.'t 0( *or 8$+'l( i# $##i)n2 to
loc$tion 000;H5 I* E8trn$l Intrr.'t 0 i# .#2( it# #r6ic ro.tin +.#t -)in $t loc$tion
000;H5 I* t! intrr.'t i# not .#2( it# #r6ic loc$tion i# $6$il$-l $# )nr$l '.r'o#
'ro)r$+ ++or15 T! intrr.'t #r6ic loc$tion# $r #'$c2 $t 8&-1t intr6$l#9
000;H *or E8trn$l Intrr.'t 0( 000BH *or Ti+r 0(
001;H *or E8trn$l Intrr.'t 1( 001BH *or Ti+r 1( $n2 #o on5 I* $n intrr.'t #r6ic
ro.tin i# #!ort no.)! 3$# i# o*tn t! c$# in control $''lic$tion#4( it c$n r#i2 ntirl1
%it!in t!$t 8&-1t intr6$l5 Lon)r #r6ic ro.tin# c$n .# $ F.+' in#tr.ction to #>i'
o6r #.-#@.nt intrr.'t loc$tion#( i* ot!r intrr.'t# $r in .#5 T! lo%#t $22r### o*
'ro)r$+ ++or1 c$n - it!r in t! on&c!i' Fl$#! or in $n 8trn$l ++or15 To +$>
t!i# #lction( #tr$' t! E8trn$l Acc## 3EA4 'in to it!r VCC or AND5 For 8$+'l( in
t! AT8"C51 %it! /0 -1t# o* on&c!i' Fl$#!( i* t! EA 'in i# #tr$''2 to VCC( 'ro)r$+
*tc!# to $22r### 0000H t!ro.)! 0FFFH $r 2irct2 to t! intrn$l Fl$#!5 Pro)r$+
*tc!# to $22r### 1000H t!ro.)! FFFFH $r 2irct2 to 8trn$l ++or15 In t!
AT8"C5: 380 -1t# Fl$#!4( EA E VCC #lct# $22r### 0000H t!ro.)! 1FFFH to -
intrn$l $n2 $22r### :000H t!ro.)! FFFFH to - 8trn$l5 I* t! EA 'in i# #tr$''2 to
AND( $ll 'ro)r$+ *tc!# $r 2irct2 to 8trn$l ++or15 T! r$2 #tro- to 8trn$l
++or1( P,EN( i# .#2 *or $ll 8trn$l 'ro)r$+ *tc!#5 Intrn$l 'ro)r$+ *tc!# 2o not
$cti6$t P,EN5 T! !$r2%$r con*i).r$tion *or 8trn$l 'ro)r$+ 8c.tion5 Not t!$t 1=
I<O lin# 3Port# 0 $n2 :4 $r 22ic$t2 to -.# *.nction# 2.rin) 8trn$l 'ro)r$+ ++or1
*tc!#5 Port 0 #r6# $# $ +.lti'l82 $22r##<2$t$ -.#5 It +it# t! lo% -1t o* t!
Pro)r$+ Co.ntr 3PCL4 $# $n $22r## $n2 t!n )o# into $ *lo$t #t$t %!il %$itin) *or
t! $rri6$l o* t! co2 -1t *ro+ t! 'ro)r$+ ++or15 D.rin) t! ti+ t!$t t! lo% -1t
o* t! Pro)r$+ Co.ntr i# 6$li2 on P0( t! #i)n$l ALE 3A22r## L$tc! En$-l4 cloc># t!i#
-1t into $n $22r## l$tc!5 M$n%!il( Port : +it# t! !i)! -1t o* t! Pro)r$+ Co.ntr
3PCH45 T!n P,EN #tro-# t! 8trn$l ++or1( $n2 t! +icrocontrollr r$2# t! co2
-1t5
Pro%ra& $e&or(
Pro)r$+ ++or1 $22r### $r $l%$1# 1= -it# %i2( 6n t!o.)! t! $ct.$l $+o.nt o*
'ro)r$+ ++or1 .#2 +$1 - l## t!$n =/0 -1t#5 E8trn$l 'ro)r$+ 8c.tion #$cri*ic#
t%o o* t! 8&-it 'ort#( P0 $n2 P:( to t! *.nction o* $22r##in) t! 'ro)r$+ ++or15
Data $e&or(
T! ri)!t !$l* o* t! intrn$l $n2 8trn$l 2$t$ ++or1 #'$c# $6$il$-l on At+l7# Fl$#!
+icrocontrollr#5 H$r2%$r con*i).r$tion *or $cc##in) .' to :0 -1t# o* 8trn$l RAM5
In t!i# c$#( t! CPU 8c.t# *ro+ intrn$l Fl$#!5 Port 0 #r6# $# $ +.lti'l82
$22r##<2$t$ -.# to t! RAM( $n2 ; lin# o* Port : $r .#2 to '$) t! RAM5 T! CPU
)nr$t# RD $n2 BR #i)n$l# $# n22 2.rin) 8trn$l RAM $cc###5 Yo. c$n $##i)n
.' to =/0 -1t# o* 8trn$l 2$t$ ++or15 E8trn$l 2$t$ ++or1 $22r### c$n - it!r 1
or : -1t# %i25 On&-1t $22r### $r o*tn .#2 in conF.nction %it! on or +or ot!r
I<O lin# to '$) t! RAM5 T%o&-1t $22r### c$n $l#o - .#2( in %!ic! c$# t! !i)!
$22r## -1t i# +itt2 $t Port :5
Intrn$l 2$t$ ++or1 $22r### $r $l%$1# 1 -1t %i2( %!ic! i+'li# $n $22r## #'$c
o* onl1 :5= -1t#5 Ho%6r( t! $22r##in) +o2# *or intrn$l RAM c$n in *$ct
$cco++o2$t ;8/ -1t#5 Dirct $22r### !i)!r t!$n GFH $cc## on ++or1 #'$c $n2
in2irct $22r### !i)!r t!$n GFH $cc## $ 2i**rnt ++or1 #'$c5 T!.#( t! U''r 1:8
$n2 ,FR #'$c occ.'1in) t! #$+ -loc> o* $22r###( 80H t!ro.)! FFH( $lt!o.)! t!1
$r '!1#ic$ll1 #'$r$t ntiti#5 T! lo%#t ;: -1t# $r )ro.'2 into / -$n># o* 8
r)i#tr#5 Pro)r$+ in#tr.ction# c$ll o.t t!# r)i#tr# $# R0 t!ro.)! RG5 T%o -it# in t!
Pro)r$+ ,t$t.# Bor2 3P,B4 #lct %!ic! r)i#tr -$n> i# in .#5 T!i# $rc!itct.r $llo%#
+or **icint .# o* co2 #'$c( #inc r)i#tr in#tr.ction# $r #!ortr t!$n in#tr.ction#
t!$t .# 2irct $22r##in)5
Pro%ra&&in% Stat*s :or#!
Te "nstr*ction Set
All ++-r# o* t! At+l +icrocontrollr *$+il1 8c.t t! #$+ in#tr.ction #t5 T!i#
in#tr.ction #t i# o'ti+i?2 *or 8& -it control $''lic$tion# $n2 it 'ro6i2# $ 6$rit1 o* *$#t
$22r##in) +o2# *or $cc##in) t! intrn$l RAM to *$cilit$t -1t o'r$tion# on #+$ll
2$t$ #tr.ct.r#5 T! in#tr.ction #t 'ro6i2# 8tn#i6 #.''ort *or 1&-it 6$ri$-l# $# $
#'$r$t 2$t$ t1'( $llo%in) 2irct -it +$ni'.l$tion in control $n2 lo)ic #1#t+# t!$t
[email protected] Bool$n 'roc##in)5 T! *ollo%in) o6r6i% o* t! in#tr.ction #t )i6# $ -ri*
2#cri'tion o* !o% crt$in in#tr.ction# c$n - .#25
Pro%ra& Stat*s :or#
T! Pro)r$+ ,t$t.# Bor2 3P,B4 cont$in# #t$t.# -it# t!$t r*lct t! c.rrnt #t$t o* t!
CPU5 T! P,B( #!o%n in Fi).r 11( r#i2# in ,FR #'$c5 T! P,B cont$in# t! C$rr1
-it( t! A.8ili$r1 C$rr1 3*or BCD o'r$tion#4( t! t%or)i#tr -$n> #lct -it#( t!
O6r*lo% *l$)( $ P$rit1 -it( $n2 t%o .#r&2*in$-l #t$t.# *l$)#5 T! C$rr1 -it( in $22ition
to #r6in) $# $ C$rr1 -it in $rit!+tic o'r$tion#( $l#o #r6# $# t! HAcc.+.l$torI *or $
n.+-r o* Bool$n o'r$tion#5
T! -it# R,0 $n2 R,1 #lct on o* t! *o.r r)i#tr -$n># #!o%n in Fi).r 85 A n.+-r
o* in#tr.ction# r*r to t!# RAM loc$tion# $# R0 t!ro.)! RG5 T! #t$t.# o* t! R,0 $n2
R,1 -it# $t 8c.tion ti+ 2tr+in# %!ic! o* t! *o.r -$n># i# #lct25 T! P$rit1 -it
r*lct# t! n.+-r o* 1# in t! Acc.+.l$tor9 PE1 i* t! Acc.+.l$tor cont$in# $n o22
n.+-r o* 1#( $n2 PE0 i* t! Acc.+.l$tor cont$in# $n 6n n.+-r o* 1#5 T!.#( t!
n.+-r o* 1# in t! Acc.+.l$tor 'l.# P i# $l%$1# 6n5 T%o -it# in t! P,B $r
.nco++itt2 $n2 c$n - .#2 $# )nr$l '.r'o# #t$t.# *l$)#5
A##ressin% $o#es
T! $22r##in) +o2# in t! Fl$#! +icrocontrollr in#tr.ction #t $r $# *ollo%#5
Direct A##ressin%
In 2irct $22r##in)( t! o'r$n2 i# #'ci*i2 -1 $n 8&-it $22r## *il2 in t! in#tr.ction5
Onl1 intrn$l 2$t$ RAM $n2 ,FR# c$n - 2irctl1 $22r##25
"n#irect A##ressin%
In in2irct $22r##in)( t! in#tr.ction #'ci*i# $ r)i#tr t!$t cont$in# t! $22r## o* t!
o'r$n25 Bot! intrn$l $n2 8trn$l RAM c$n - in2irctl1 $22r##25 T! $22r##
r)i#tr *or 8&-it $22r### c$n - it!r t! ,t$c> Pointr or R0 or R1 o* t! #lct2
r)i#tr -$n>5 T! $22r## r)i#tr *or 1=&-it $22r### c$n - onl1 t! 1=&-it 2$t$ 'ointr
r)i#tr( DPTR5
Re%ister "nstr*ctions
T! r)i#tr -$n>#( %!ic! cont$in r)i#tr# R0 t!ro.)! RG( c$n - $cc##2 -1
in#tr.ction# %!o# o'co2# c$rr1 $ ;& -it r)i#tr #'ci*ic$tion5 In#tr.ction# t!$t $cc##
t! r)i#tr# t!i# %$1 +$> **icint .# o* co2( #inc t!i# +o2 li+in$t# $n $22r##
-1t5 B!n t! in#tr.ction i# 8c.t2( on o* t! i)!t r)i#tr# in t! #lct2 -$n> i#
$cc##25 On o* *o.r -$n># i# #lct2 $t 8c.tion ti+ -1 t! t%o -$n> #lct -it# in
t! P,B5
Re%ister1Speci+ic "nstr*ctions
,o+ in#tr.ction# $r #'ci*ic to $ crt$in r)i#tr5 For 8$+'l( #o+ in#tr.ction# $l%$1#
o'r$t on t! Acc.+.l$tor( #o no $22r## -1t i# n22 to 'oint to it5 In t!# c$##( t!
o'co2 it#l* 'oint# to t! corrct r)i#tr5 In#tr.ction# t!$t r*r to t! Acc.+.l$tor $# A
$##+-l $# Acc.+.l$tor&#'ci*ic o'co2#5
"n#e6e# A##ressin%
Pro)r$+ ++or1 c$n onl1 - $cc##2 6i$ in282 $22r##in)5 T!i# $22r##in) +o2 i#
intn22 *or r$2in) loo>&.' t$-l# in 'ro)r$+ ++or15 A 1=&-it -$# r)i#tr 3it!r
DPTR or t! Pro)r$+ Co.ntr4 'oint# to t! -$# o* t! t$-l( $n2 t! Acc.+.l$tor i# #t
.' %it! t! t$-l ntr1 n.+-r5 T! $22r## o* t! t$-l ntr1 in 'ro)r$+ ++or1 i#
*or+2 -1 $22in) t! Acc.+.l$tor 2$t$ to t! -$# 'ointr5 Anot!r t1' o* in282
$22r##in) i# .#2 in t! Hc$# F.+'I in#tr.ction5 In t!i# c$# t! 2#tin$tion $22r## o* $
F.+' in#tr.ction i# co+'.t2 $# t! #.+ o* t! -$# 'ointr $n2 t! Acc.+.l$tor 2$t$5
LCD 2L";3"D CR<STAL D"SPLA<4
Liquid Crystal Display Fundamentals
[email protected] Cr1#t$l Di#'l$1# 3LCD#4 $r c$t)ori?2 $# non +i##i6 2i#'l$1 26ic#( in t!$t
r#'ct( t!1 2o not 'ro2.c $n1 *or+ o* li)!t li> $ C$t!o2 R$1 T.- 3CRT45 LCD#
it!r '$## or -loc> li)!t t!$t i# r*lct2 *ro+ $n 8trn$l li)!t #o.rc or 'ro6i22 -1 $
-$c><#i2 li)!tin) #1#t+5 T!r $r t%o +o2# o* o'r$tion *or LCD# 2.rin) t! $-#nc
o* $n lctric *il2 3$''li2 Po%r4K $ +o2 2#cri-# t! tr$n#+itt$nc #t$t o* t! [email protected]
cr1#t$l l+nt#5 Nor+$l B!it +o29 t! 2i#'l$1 i# %!it or cl$r $n2 $llo%# li)!t to
'$## t!ro.)! $n2 Nor+$l Bl$c> Mo29 t! 2i#'l$1 i# 2$r> $n2 $ll li)!t i# 2i**.#25
Virt.$ll1 $ll 2i#'l$1# in 'ro2.ction *or PC<Bor>#t$tion .# $r nor+$l %!it +o2 to
o'ti+i? contr$#t $n2 #'25
A #i+'li*i2 2#cri'tion o* !o% $ 2ot +$tri8 LCD 2i#'l$1 %or># i# $# *ollo%#9 A t%i#t2
n+$tic 3TN4 LC 2i#'l$1 con#i#t# o* t%o 'ol$ri?r( t%o 'ic# o* )l$##( #o+ *or+ o*
#%itc!in) l+nt or lctro2 to 2*in 'i8l#( $n2 2ri6r Int)r$t2 Circ.it# 3IC#4 to
$22r## t! ro%# $n2 col.+n# o* 'i8l#5 To 2*in $ 'i8l 3or #.- 'i8l l+nt *or $
color 2i#'l$14( $ rct$n)l i# con#tr.ct2 o.t o* In2i.+ Tin O8i2 && $ #+i&tr$n#'$rnt
+t$l o8i2 3ITO4 $n2 c!$r) i# $''li2 to t!i# $r$ in or2r to c!$n) t! orint$tion o*
t! LC +$tri$l 3 c!$n) *ro+ $ %!it 'i8l to $ 2$r> 'i8l45 T! +t!o2 .tili?2 to *or+
$ 'i8l in '$##i6 $n2 $cti6 +$tri8 2i#'l$1# 2i**r# $n2 %ill - 2#cri-2 in l$tr
#ction#5 Fi).r 1 ill.#tr$t# $ cro## #ction$l 6i% o* $ #i+'l TN LC 2i#'l$15 Fi).r :
2'ict# $ 2ot +$tri8 2i#'l$1 $# 6i%2 %it!o.t it# +t$l +o2.l<c$# 8'o#in) t! IC
2ri6r#5
Loo>in) 2irctl1 $t t! 2i#'l$1 t! )$t or ro% 2ri6r# $r loc$t2 it!r on t! l*t or t!
ri)!t #i2 o* t! 2i#'l$1 %!il t! 2$t$ or col.+n 2ri6r# $r loc$t2 on t! to' 3$n2 or
-otto+4 o* t! 2i#'l$15 N% t!in 2i#'l$1 +o2.l tc!nolo)1 +o.nt# t! IC# on
con2.cti6 t$' t!$t $llo%# t!+ to - *ol22 -!in2 t! 2i#'l$1 *.rt!r r2.cin) t! #i?
o* t! *ini#!2 +o2.l5 An IC %ill $22r## $ n.+-r o* ro%# or col.+n#5
Fi).r 19 Cro## ,ction o* $ ,i+'l LC Di#'l$1
viewer
///////////////////////////////////// Polarizer
_____________________________________ glass
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Liquid Crystal
_____________________________________ glass
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ Polarizer
Backlight
Fi).r :9 LCD '$nl $n2 IC 2ri6r loc$tion#
________________________________________
| |
| IC IC | Source/Colu! ICs
| | |
| | |
|IC"""""""""""""""""""""Pi#el |
| |
|IC $"""" %ate Li!e/&ow IC |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
L An IC 2ri6r %ill $22r## $ n.+-r o* ro%<col.+n lin# $n2 not F.#t t! #in)l 'i8l in
t! 2i$)r$+ $-o6
Pol$ri?r# $r $n int)r$l '$rt o* $ LCD 2i#'l$1( 'o####in) t! .ni@. 'ro'rt1 o* onl1
'$##in) li)!t i* it i# orint2 in $ #'ci*ic 3orint24 2irction5 To .tili? t!i# '!no+non
in TN LC 2i#'l$1#( t! -otto+ 'ol$ri?r orint# inco+in) li)!t in on 2irction5 T!
orint2 li)!t '$### t!ro.)! t! LC +$tri$l $n2 i# it!r .n$ltr2 or M-ntM "0 2)r#5
D'n2in) on t! orint$tion o* t! to' 'ol$ri?r( t!i# li)!t %ill it!r '$## t!ro.)! or -
2i**.#25 I* t! li)!t i# 2i**.#2( it %ill $''$r $# $ 2$r> $r$5 Fi).r ; i# $ #i+'l
ill.#tr$tion o* t! #@.nc o* 6nt# t!$t occ.r %!n li)!t '$### t!ro.)! $ #i+'l
t%i#t2 n+$tic LC 2i#'l$15
%i?ui# Cr+stal Material1
T! [email protected] cr1#t$l# .#2 *or 2i#'l$1 tc!nolo)1 $r t!r+otro'ic [email protected] cr1#t$l#K t!1
8!i-it 2#ir2 c!$r$ctri#tic# o6r $ #'ci*ic t+'r$t.r r$n)5 T!i# i# t! 'ri+$r1
r$#on %!1 LCD# 2o not o'r$t 'ro'rl1 %!n t!1 $r too col2 or too %$r+5 I* [email protected]
cr1#t$l# $r too col2( t!1 %ill not t%i#t $n2 t! 2i#'l$1 %ill not *or+ $n i+$)5 I* t!
2i#'l$1 i# too %$r+( t! r#i#t$nc o* t! [email protected] cr1#t$l +$tri$l c!$n)# $n2 t!i# $ltr#
t! 'ro'rti# o* t! 2i#'l$1 $n2 'r*or+$nc #.**r#5 [email protected] cr1#t$l +$tri$l *or 2i#'l$1
.# i# nor+$ll1 r*rr2 to $# TN 3,TN( D,TN( M,TN( $n2 tc54 or T%i#t2 N+$tic&&
#o+ti+# >no%n $# TNFE or T%i#t2 N+$tic Fil2 E**ct5 It i# c$ll2 TBI,TED #inc
t! cr1#t$l# $r t%i#t2 "0 2)r# 3or +or *or ,TN4 *ro+ t! to' 'ic o* )l$## to t!
-otto+ 'ic o* )l$##5 3TN .#.$ll1 r*r# onl1 to $ "0 2)r t%i#t54 Fil2 E**ct 3$ 2irct
corrl$tion i# t! #+icon2.ctor MO,FET4( r*r# to t! LC +$tri$lN# $-ilit1 to $li)n
'$r$lll or 'r'n2ic.l$r to $n $''li2 lctric *il25 A# $ r#.lt( .#in) t%i#t2 or
.nt%i#t2 [email protected] cr1#t$l $n2 t%o 'ol$ri?r#K $n $''li2 lctric *il2 c$n *orc t! LC
+$tri$l into $ '$rtic.l$r $li)n+nt **cti6l1 2i**.#in) or '$##in) li)!t t!ro.)! t! to'
'ol$ri?r5
A# $ not o* intr#t( 'ol$ri?r# $r $l#o on o* t! +$For r$#on# t!$t LC 2i#'l$1# [email protected]
-ri)!t -$c> li)!tin)5 T! 'ol$ri?r# $n2 [email protected] cr1#t$l +$tri$l# $-#or- +or t!$n 50O o*
t! inci2nt li)!t5 A# $ r#.lt( 6n t!o.)! t! $ct.$l 2i#'l$1 i# $ 6r1 lo% 'o%r 26ic(
t! 'o%r !.n)r1 -$c> li)!tin) +$># $ LCD +o2.l on o* t! 'ri+$r1 c$.## o* #!ort
-$ttr1 li* in not-oo> co+'.tr#5 D. to t! *$ct t!$t t! LC +$tri$l !$# o'tic$l
'ro'rti# $n2 **cti6l1 -n2# li)!t( t! 'ro-l+ o* 6i%in) $n)l **ct# occ.r5 B!n
t! .#r i# not 2irctl1 in *ront o* t! 2i#'l$1 t! i+$) c$n 2i#$''$r or #+ to in6rt
32$r> i+$)# -co+ li)!t $n2 li)!t i+$)# -co+ 2$r>45 Ho%6r( LC +$tri$l $n2
'ol$ri?r tc!nolo)1 i# r$'i2l1 i+'ro6in) $n2 t!$t i+'ro6+nt i# #!o%in) .' in -ri)!tr
2i#'l$1# %it! )r$tr 6i%in) $n)l#5
%i?ui# Cr+stal Ali0nment
[email protected] cr1#t$l# +.#t - $li)n2 to t! to' $n2 -otto+ 'ic# o* )l$## in or2r to o-t$in
t! 2#ir2 t%i#t5 In ot!r %or2#( t! "0 2)r t%i#t i# *or+2 -1 $nc!orin) t! [email protected]
cr1#t$l on on )l$## 'l$t $n2 *orcin) it to t%i#t $cro## t! cll )$' 3t! 2i#t$nc -t%n
t! t%o )l$## 'l$t#4 %!n cont$ctin) t! #con2 'l$t5 F.rt!r+or( T! $ct.$l i+$)
@.$lit1 o* t! 2i#'l$1 %ill - 2'n2nt on t! #.r*$c $li)n+nt o* t! LC +$tri$l5 T!
+t!o2 c.rrntl1 .#2 *or $li)nin) [email protected] cr1#t$l# %$# 26lo'2 -1 t! D$i&Ni''on
,crnin) 3En)li#!E Bi) J$'$n ,crnin)4 Co+'$n15 T! 'roc## con#i#t# o* co$tin) t!
to' $n2 -otto+ #!t# o* )l$## %it! $ Pol1i+i2 -$#2 *il+5 T! to' 'ic o* )l$## i#
co$t2 $n2 r.--2 in $ '$rtic.l$r orint$tionK t! -otto+ '$nl<'ol1i+i2 i# r.--2
'r'n2ic.l$r 3"0 2)r# *or TN 2i#'l$1#4 %it! r#'ct to t! to' '$nl5 It %$#
2i#co6r2 t!$t -1 r.--in) t! 'ol1i+i2 %it! $ clot!( n$no+tr 31 C 10 & " +tr#4 #i?
)roo6# $r *or+2 $n2 t! [email protected] cr1#t$l# $li)n %it! t! 2irction o* t! )roo6#5 It i#
co++on t!$t %!n $##+-lin) $ TN LC cll( it %ill - nc##$r1 to li+in$t '$tc!# o*
non .ni*or+ $r$#5 T! t%o '$r$+tr# [email protected] to li+in$t t! non .ni*or+iti# $n2
co+'lt t! TN LC 2i#'l$1 $r 'rtilt $n)l $n2 c!ol#tric i+'.riti#5 TN LC cll#
co++onl1 !$6 t%o 'ro-l+# t!$t $**ct .ni*or+it1 *ollo%in) $##+-l19 r6r# tilt $n2
r6r# t%i#t5 R6r# tilt i# $ *.nction o* t! $''li2 lctric$l *il2 $n2 r6r# t%i#t i#
co++on %!n no lctric$l *il2 i# $''li25 R6r# t%i#t i# li+in$t2 -1 t!
intro2.ction o* c!ol#tric $22iti6# $n2 r6r# tilt i# li+in$t2 -1 intro2.cin) $ 'r&tilt
$n)l to t! LC +$tri$l5 T! 'r&tilt $n)l $l#o 2tr+in# %!$t 2irction t! LC
+olc.l# %ill rot$t %!n $n lctric$l *il2 i# $''li25 Pr&tilt $n)l c$n - 6i#.$li?2
-1 con#i2rin) t! nor+$l 'o#ition o* t! LC +olc.l to - *l$t $)$in#t t! )l$## 'l$t(
-1 $nc!orin) on 2) $n2 *orcin) t! ot!r .'%$r2 -1 $ #'ci*ic n.+-r o* 2)r#( $
'rtilt $n)l i# #t$-li#!25
DS1621 (Digital herm!meter and herm!stat"
'EAT3RES
P T+'r$t.r +$#.r+nt# [email protected] no 8trn$l co+'onnt#
P M$#.r# t+'r$t.r# *ro+ Q55RC to S1:5RC in 055RC incr+nt#5 F$!rn!it
@.i6$lnt i# Q=GRF to :5GRF in 05"RF incr+nt#
P T+'r$t.r i# r$2 $# $ "Q-it 6$l. 3t%o -1t tr$n#*r4
P Bi2 'o%r #.''l1 r$n) 3:5GV to 555V4
P Con6rt# t+'r$t.r to 2i)it$l %or2 in 1 #con2
P T!r+o#t$tic #ttin)# $r .#r 2*in$-l $n2 non6ol$til
P D$t$ i# r$2 *ro+<%rittn 6i$ $ :Q%ir #ri$l intr*$c 3o'n 2r$in I<O lin#4
P A''lic$tion# incl.2 t!r+o#t$tic control#( in2.#tri$l #1#t+#( con#.+r 'ro2.ct#(
t!r+o+tr#( or $n1 t!r+$l #n#iti6 #1#t+5
P 8Q'in DIP or ,OIC '$c>$) 3150 MIL $n2 :08 MIL4
P"N D"SCR"PT"ON!
,DA Q :QBir ,ri$l D$t$ In'.t<O.t'.t
,CL Q :QBir ,ri$l Cloc>
AND Q Aro.n2
TOUT Q T!r+o#t$t O.t'.t ,i)n$l
A0 Q C!i' A22r## In'.t
A1 Q C!i' A22r## In'.t
A: Q C!i' A22r## In'.t
VDD Q Po%r ,.''l1 Volt$)
9or> Function1
T! D,1=:1 2i)it$l t!r+o+tr $n2 t!r+o#t$t 'ro6i2# "Q-it t+'r$t.r r$2in)#
%!ic! in2ic$t t! t+'r$t.r o* t! 26ic5 T! t!r+$l $l$r+ o.t'.t( TOUT( i# $cti6
%!n t! t+'r$t.r o* t! 26ic 8c2# $ .#rQ2*in2 t+'r$t.r TH5 T! o.t'.t
r+$in# $cti6 .ntil t! t+'r$t.r 2ro'# -lo% .#r 2*in2 t+'r$t.r TL( $llo%in)
*or $n1 !1#tr#i# nc##$r15 U#r 2*in2 t+'r$t.r #ttin)# $r #tor2 in nonQ 6ol$til
++or1( #o '$rt# +$1 - 'ro)r$++2 'rior to in#rtion in $ #1#t+5 T+'r$t.r
#ttin)#( $n2 t+'r$t.r r$2in)# $r $ll co++.nic$t2 to<*ro+ t! D,1=:1 o6r $
#i+'l :Q%ir #ri$l intr*$c5
Operation o+ De/ice DS1821!
A -loc> 2i$)r$+ o* t! D,1=:1 i# #!o%n in Fi).r $-o65T! D,1=:1 +$#.r#
t+'r$t.r# t!ro.)! t! .# o* $n onQ-o$r2 'ro'rit$r1 t+'r$t.r +$#.r+nt
[email protected] T! D,1=:1 +$#.r# t+'r$t.r -1 co.ntin) t! n.+-r o* cloc> c1cl#
t!$t $n o#cill$tor %it! $ lo% t+'r$t.r co**icint )o# t!ro.)! 2.rin) $ )$t 'rio2
2tr+in2 -1 $ !i)! t+'r$t.r co**icint o#cill$tor5 T! co.ntr i# 'r#t %it! $ -$#
co.nt t!$t corr#'on2# to Q55RC5 I* t! co.ntr r$c!# ?ro -*or t! )$t 'rio2 i#
o6r( t! t+'r$t.r r)i#tr( %!ic! i# $l#o 'r#t to t! Q55RC 6$l.( i# incr+nt2(
in2ic$tin) t!$t t! t+'r$t.r i# !i)!r t!$n Q55RC5 At t! #$+ ti+( t! co.ntr i# t!n
'r#t %it! $ 6$l. 2tr+in2 -1 t! #lo' $cc.+.l$tor circ.itr15 T!i# circ.itr1 i#
n22 to co+'n#$t *or t! '$r$-olic -!$6ior o* t! o#cill$tor# o6r t+'r$t.r5 T!
co.ntr i# t!n cloc>2 $)$in .ntil it r$c!# ?ro5 I* t! )$t 'rio2 i# #till not *ini#!2(
t!n t!i# 'roc## r'$t#5 T! #lo' $cc.+.l$tor i# .#2 to co+'n#$t *or t! nonlin$r
-!$6ior o* t! o#cill$tor# o6r t+'r$t.r( 1il2in) $ !i)! r#ol.tion t+'r$t.r
+$#.r+nt5 T!i# i# 2on -1 c!$n)in) t! n.+-r o* co.nt# nc##$r1 *or t! co.ntr to
)o t!ro.)! *or $c! incr+nt$l 2)r in t+'r$t.r5 To o-t$in t! 2#ir2 r#ol.tion(
t!r*or( -ot! t! 6$l. o* t! co.ntr $n2 t! n.+-r o* co.nt# 'r RC 3t! 6$l. o* t!
#lo' $cc.+.l$tor4 $t $ )i6n t+'r$t.r +.#t - >no%n5 T!i# c$lc.l$tion i# 2on in#i2
t! D,1=:1 to 'ro6i2 055RC r#ol.tion5 T! t+'r$t.r r$2in) i# 'ro6i22 in $ "Q-it(
t%o7# co+'l+nt r$2in) -1 i##.in) t! READ TEMPERATURE co++$n25 T! 2$t$ i#
tr$n#+itt2 t!ro.)! t! :Q%ir #ri$l intr*$c( M,B *ir#t5 T! D,1=:1 c$n +$#.r
t+'r$t.r o6r t! r$n) o* Q55RC to S1:5RC in 055RC incr+nt#5 For F$!rn!it
.#$)( $ loo>.' t$-l or con6r#ion *$ctor +.#t - .#25
,inc 2$t$ i# tr$n#+itt2 o6r t! :Q%ir -.# M,B *ir#t( t+'r$t.r 2$t$ +$1 - %rittn
to<r$2 *ro+ t! D,1=:1 $# it!r $ #in)l -1t 3%it! t+'r$t.r r#ol.tion o* 1RC4( or
$# t%o -1t#( t! #con2 -1t cont$inin) t! 6$l. o* t! l$#t #i)ni*ic$nt 3055RC4-it o* t!
t+'r$t.r r$2in)( $# #!o%n in T$-l $-o65 Not t!$t t! r+$inin) G -it# o* t!i# -1t
$r #t to $ll 07#5 Not t!$t t+'r$t.r i# r'r#nt2 in t! D,1=:1 in tr+# o* $ 1<:RC
L,B( 1il2in) t! *ollo%in) "Q-it *or+$t9
Hi)!r r#ol.tion# +$1 - o-t$in2 -1 r$2in) t! t+'r$t.r( $n2 tr.nc$tin) t! 055RC
-it 3t! L,B4 *ro+ t! r$2 6$l.5 T!i# 6$l. i# TEMPTREAD5 T! 6$l. l*t in t!
co.ntr +$1 t!n - r$2 -1 i##.in) $ READ COUNTER co++$n25 T!i# 6$l. i# t!
co.nt r+$inin) 3COUNTTREMAIN4 $*tr t! )$t 'rio2 !$# c$#25 B1 lo$2in) t!
6$l. o* t! #lo' $cc.+.l$tor into t! co.nt r)i#tr 3.#in) t! READ ,LOPE
co++$n24( t!i# 6$l. +$1 t!n - r$2( 1il2in) t! n.+-r o* co.nt# 'r 2)r C
3COUNTTPERTC4 $t t!$t t+'r$t.r5 T! $ct.$l t+'r$t.r +$1 - t!n - c$lc.l$t2
-1 t! .#r .#in) t! *ollo%in)9
Ter&ostat Control!
In it# o'r$tin) +o2( t! D,1=:1 *.nction# $# $ t!r+o#t$t %it! 'ro)r$++$-l
!1#tr#i#5 T! t!r+o#t$t o.t'.t .'2$t# $# #oon $# $ t+'r$t.r con6r#ion i#
co+'lt5 B!n t! D,1=:17# t+'r$t.r +t# or 8c2# t! 6$l. #tor2 in t! !i)!
t+'r$t.r tri' r)i#tr 3TH4( t! o.t'.t -co+# $cti6( $n2 %ill #t$1 $cti6 .ntil t!
t+'r$t.r *$ll# -lo% t! t+'r$t.r #tor2 in t! lo% t+'r$t.r tri))r r)i#tr
3TL45 In t!i# %$1( $n1 $+o.nt o* !1#tr#i# +$1 - o-t$in25 T! $cti6 #t$t *or t!
o.t'.t i# 'ro)r$++$-l -1 t! .#r( #o t!$t $n $cti6 #t$t +$1 it!r - $ lo)ic 1 3VDD4
or $ lo)ic 0 30V45
&ata Transer1
T! D,1=:1 #.''ort# $ -iQ2irction$l t%oQ%ir -.# $n2 2$t$ tr$n#+i##ion 'rotocol5 A
26ic t!$t #n2# 2$t$ onto t! -.# i# 2*in2 $# $ tr$n#+ittr( $n2 $ 26ic rci6in) 2$t$
$# $ rci6r5 T! 26ic t!$t control# t! +##$) i# c$ll2 $ H+$#trI5 T! 26ic# t!$t
$r controll2 -1 t! +$#tr $r H#l$6#I5 T! -.# +.#t - controll2 -1 $ +$#tr 26ic
%!ic! )nr$t# t! #ri$l cloc> 3,CL4( control# t! -.# $cc##( $n2 )nr$t# t! ,TART
$n 2 ,TOP con2ition#5 T! D,1=:1 o'r$t# $# $ #l$6 on t! t%oQ%ir -.#5 Connction#
to t! -.# $r +$2 6i$ t! o'nQ2r$in I<O lin# ,DA $n2 ,CL5 T! *ollo%in) -.#
'rotocol !$# -n 2*in25
P D$t$ tr$n#*r +$1 - initi$t2 onl1 %!n t! -.# i# not -.#15
P D.rin) 2$t$ tr$n#*r( t! 2$t$ lin +.#t r+$in #t$-l %!n6r t! cloc> lin i# HIAH5
C!$n)# in t! 2$t$ lin %!il t! cloc> lin i# !i)! %ill - intr'rt2 $# control #i)n$l#5
Accor2in)l1( t! *ollo%in) -.# con2ition# !$6 -n 2*in29
*us not -us+1 Bot! 2$t$ $n2 cloc> lin# r+$in HIAH5
Start #ata transer1 A c!$n) in t! #t$t o* t! 2$t$ lin( *ro+ HIAH to LOB( %!il t!
cloc> i# HIAH( 2*in# $ ,TART con2ition5
Sto. #ata transer1 A c!$n) in t! #t$t o* t! 2$t$ lin( *ro+ LOB to HIAH( %!il t!
cloc> lin i# HIAH( 2*in# t! ,TOP con2ition5
&ata =ali#1 T! #t$t o* t! 2$t$ lin r'r#nt# 6$li2 2$t$ %!n( $*tr $ ,TART
con2ition( t! 2$t$ lin i# #t$-l *or t! 2.r$tion o* t! HIAH 'rio2 o* t! cloc> #i)n$l5
T! 2$t$ on t! lin +.#t - c!$n)2 2.rin) t! LOB 'rio2 o* t! cloc> #i)n$l5 T!r i#
on cloc> '.l# 'r -it o* 2$t$5 E$c! 2$t$ tr$n#*r i# initi$t2 %it! $ ,TART con2ition
$n2 tr+in$t2 %it! $ ,TOP con2ition T! n.+-r o* 2$t$ -1t# tr$n#*rr2 -t%n
,TART $n2 ,TOP con2ition# i# not li+it2( $n2 i# 2tr+in2 -1 t! +$#tr 26ic5 T!
in*or+$tion i# tr$n#*rr2 -1tQ%i# $n2 $c! rci6r $c>no%l2)# %it! $ nint!Q-it5
Bit!in t! -.# #'ci*ic$tion# $ r).l$r +o2 3100 0H? cloc> r$t4 $n2 $ *$#t +o2 3/00
0H? cloc> r$t4 $r 2*in25 T! D,1=:1 %or># in -ot! +o2#5
Ac>no3le#0e1 E$c! rci6in) 26ic( %!n $22r##2( i# o-li)2 to )nr$t $n
$c>no%l2) $*tr t! rc'tion o* $c! -1t5
&ata Transmission in &S1(21 is sho3n -elo31
Co&&an# Set Ta7le!
NOTES1
15 In contin.o.# con6r#ion +o2( $ ,to' Con6rt T co++$n2 %ill !$lt contin.o.#
con6r#ion5 To r#t$rt( t! ,t$rt Con6rt T co++$n2 +.#t - i##.25 In onQ#!ot +o2( $
,t$rt Con6rt T co++$n2 +.#t - i##.2 *or 6r1 t+'r$t.r r$2in) 2#ir25
:5 Britin) to t! E: t1'ic$ll1 [email protected]# 10+# $t roo+ t+'r$t.r5 A*tr i##.in) $ %rit
co++$n2( no *.rt!r %rit# #!o.l2 - r@.#t2 *or $t l$#t 10 +#5
A)SOL3TE $AX"$3$ RAT"NGS
Volt$) on An1 Pin Rl$ti6 to Aro.n2 Q055V to SG50V
O'r$tin) T+'r$t.r Q55RC to S1:5RC
,tor$) T+'r$t.r Q55RC to S1:5RC
,ol2rin) T+'r$t.r :=0RC *or 10 #con2#
,.''l1 Volt$) in DC Q ,1+-ol VDD Min5 :5G to M$85 555 6olt#5
Volta0e 8e0ulator 7C @Electrical Characteristics o MC,805A1
T! MCG8CC<LMG8CC<MCG8CCA #ri# o* t!r tr+in$l 'o#iti6 r).l$tor# $r
$6$il$-l in t! TO&::0<D&PA0 '$c>$) $n2 %it! #6r$l *i82 o.t'.t 6olt$)#( +$>in)
t!+ .#*.l in $ %i2 r$n) o* $''lic$tion#5 E$c! t1' +'lo1# intrn$l c.rrnt li+itin)(
t!r+$l #!.t 2o%n $n2 #$* o'r$tin) $r$ 'rotction( +$>in) it ##nti$ll1
in2#tr.cti-l5 I* $2@.$t !$t #in>in) i# 'ro6i22( t!1 c$n 2li6r o6r 1A o.t'.t
c.rrnt5 Alt!o.)! 2#i)n2 'ri+$ril1 $# *i82 6olt$) r).l$tor#( t!# 26ic# c$n -
.#2 %it! 8trn$l co+'onnt# to o-t$in $2F.#t$-l 6olt$)# $n2 c.rrnt#5
'eat*res
P O.t'.t C.rrnt .' to 1A
P O.t'.t Volt$)# o* 5( =( 8( "( 10( 1:( 15( 18( :/V
P T!r+$l O6rlo$2 Protction
P ,!ort Circ.it Protction
P O.t'.t Tr$n#i#tor ,$* O'r$tin) Ar$ Protction
Pin Di$)r$+ o* t! Po%r IC
T(pical Applications
Notes1
314 To #'ci*1 $n o.t'.t 6olt$)5 #.-#tit.t 6olt$) 6$l. *or MCC5M A co++on )ro.n2 i#
[email protected] -t%n t! in'.t $n2 t! O.t'.t 6olt$)5 T! in'.t 6olt$) +.#t r+$in
t1'ic$ll1 :50V $-o6 t! o.t'.t 6olt$) 6n 2.rin) t! lo% 'oint on t! in'.t ri''l
6olt$)5
3:4 CI i# [email protected] i* r).l$tor i# loc$t2 $n $''rci$-l 2i#t$nc *ro+ 'o%r ,.''l1 *iltr5
3;4 CO i+'ro6# #t$-ilit1 $n2 tr$n#int r#'on#5
S=CE$AT"C D"AGRA$!
)loc9 Dia%ra& o+ te&perat*re in#icator *sin% "C,-C.2!
CONST8'CT7ON AN& 9O867NB OF T;E C78C'7T
T! *i).r $-o6 #!o%# t! -$#ic -loc> 2i$)r$+ o* t! t+'r$t.r in2ic$tor #1#t+
.#in) +icrocontrollr AT8"C5:5 T! 'o%r #.''l1 *or t! circ.it i# r).l$t2 -1 t!
ICG805 $n2 #.''li2 to 2i**rnt '$rt# o* t! .nit5 D,1=:1 i# t! t+'r$t.r #n#or c!i'5
T! +icrocontrollr .nit 3MCU4 r$2# t! t+'r$t.r *ro+ t! #n#or5 T! t+'r$t.r
2$t$ i# co+'$r2 %it! crt$in .#r&2*in t+'r$t.r 6$l.# $n2 'roc##2 in#i2 t!
MCU $# 'r t! 'ro)r$+ $n2 t!n #nt to t! LCD 2i#'l$15T! *.nction# o* $c! #ction
o* t! circ.it $r 8'l$in2 in t! *ollo%in) #ction#5
)O9E8
S'))%C

,805
8EB'%ATO8
&S1(21
TEM)8AT'8E
SENSO8
MC'
AT8!C52
%C& &7S)%AC
@1(D1A
)o3er Su..l+
T! 'o%r #.''l1 .nit con#i#t# o* $ #t'&2o%n tr$n#*or+r 3:;0V AC 'ri+$r1 to 0&"V(
:50+A #con2$r14( -ri2) rcti*ir $n2 6olt$) r).l$tor5 T! o.t'.t o* t! tr$n#*or+r i#
*2 to -ri2) rcti*ir 2io2# D1 t!ro.)! D/ 3$c! IN/00G45 T! ri''l *ro+ t! o.t'.t
-ri2) rcti*ir i# *iltr2 -1 c$'$citor C1 $n2 *2 to r).l$tor ICG8055 T! r).l$t2
o.t'.t i# )i6n to t! t+'r$t.r #n#or( +icrocontrollr .nit $n2 LCD +o2.l(
r#'cti6l15
B!n t! #%itc! ,1 i# clo#2( LED1 )lo%# to in2ic$t t! 'r#nc o* 'o%r in t!
#1#t+5
Tem.erature Sensor
T+'r$t.r #n#or c!i' D,1=:1 3IC;4 i# $n 8&'in DIP IC5 T! 'in 2t$il# o* D,1=:1 $r
#!o%n in it# 2i$)r$+ $n2 t! intrn$l -loc> 2i$)r$+ in *i).r&;5 T! c!i' c$n +$#.r
t+'r$t.r# *ro+ &55 to 1:5 2)r Cl#i.# in 055 2)r Cl#i.# incr+nt#( %!ic! $r
r$2 $# "&-it 6$l.#5 It c$n o'r$t o** :5GV to 555V5 D$t$ i# r$2 <%rittn 6i$ $ :&%ir
#ri$l intr*$c5 Pin# 1 $n2 : o* t! t+'r$t.r IC $r connct2 to 'in# 11 $n2 10 o* t!
+icrocontrollr( r#'cti6l15 T! t!r+$l $l$r+ o.t'.t 3To.t4 o* IC D,1=:1 $cti6$t#
%!n t! t+'r$t.r 8c2# .#r 2*in2 !i)! t+'r$t.r TH5 T! o.t'.t r+$in#
$cti6 .ntil t! t+'r$t.r 2ro'# -lo% .#r&2*in2 lo% t+'r$t.r Tl5 U#r&2*in2
t+'r$t.r #ttin)# $r #tor2 in t! non&6ol$til ++or15 T+'r$t.r #ttin)# $n2
t+'r$t.r r$2in)# $r $ll co++.nic$t2 to<*ro+ IC D,1=:1 o6r $ :&%ir #ri$l c$-l5
T! +o#t #i)ni*ic$nt -it 3M,B4 o* t! 2$t$ i# tr$n#+itt2 *ir#t $n2 t! l$#t #i)ni*ic$nt -it
3L,B4 i# tr$n#+itt2 l$#t5
A##ressin0
T! c!i' $22r## o* D,1=:1 co+'ri## intrn$l 'r#t co2 ni--l N1001N 3-in$r14
*ollo%2 -1 intrn$ll1 con*i).r$-l $22r## 'in#<-it# A:( A1 $n2 A05 T! i)!t! -it o* t!
$22r## -1t i# 2tr+in2 -1 t! t1' o* o'r$tion 3it!r r$2 or %rit4 t!$t i# to -
'r*or+25 For %ritin) to t! 26ic t! i)!t -it i# N0N $n2 *or r$2in) *ro+ t! 26ic t!
i)!t! -it i# N1N5 In o.r c$#( A:( A1 $n2 A0 'in# $r )ro.n22 $n2 !nc t! 26ic
$22r## *or %ritin) i# N1001000-N or "0 3!84 $n2 *or r$2in) t! 26ic $22r## i#
N10010001-N or "1 3!845
Coni0uration:Status re0ister
T!i# r)i#tr c$n - $cc##2 *or r$2in) or %ritin) -1 i##.in) co++$n2 -1t AC3!84
*ro+ t! +$#tr 38:C5:45 T!i# r)i#tr i# '$rtic.l$rl1 [email protected] i* D,1=:1 i# .#2 *or
t!r+o#t$t control( #inc it cont$in# *l$) -it# THF 3!i)!&t+'r$t.r *l$)4 %!ic! $r #t
to N1N %!n t+'r$t.r cro### t! r#'cti6 li+it# $rlir %rittn into TH $n2 TL
r)i#tr#5 It $l#o cont$in# t! *l$) -it 32on4( %!ic! i# #t to N1N %!n r#.lt# o* con6r#ion
$r $6$il$-l $*tr i##.in) o* #t$rt con6r#ion co++$n2 EE3!845 T! ot!r -it# o*
con*i).r$tion r)i#tr $r 2*in25 NNVBN i# t! non&6ol$til ++or1 -.#1 *l$)( N1N i# to
%rit to $n E: ++or1 cll in 'ro)r##( N0N in2ic$t# t!$t non&6ol$til ++or1 i# not -.#1(
NPOLN i# non&6ol$til o.t'.t 'ol$rit1 -it 3N1NE$cti6 !i)! $n2 N0N E $cti6 lo%4 $n2 N1#!otN i#
on&#!ot +o25 A co'1 to E: +$1 t$> .' to 10+#5 I* 1#!ot i# N1N( D,1=:1 %ill 'r*or+
on t+'r$t.r con6r#ion .'on rc'tion o* t! #t$rt con6rt T 'rotocol5 I* 1#!ot i# N0N(
D,1=:1 %ill contin.o.#l1 'r*or+ t+'r$t.r con6r#ion#5 T!i# -it i# non&6ol$til5
Comman# Set
Co+'lt co++$n2 in#tr.ction #t *or $cc##in) 6$rio.# intrn$l r)i#tr# $# %ll $# *or
#t$rtin) $n2 #to''in) o* con6r#ion 'roc## $r )i6n in T$-l5 For .n2r#t$n2in) t!
8$ct #@.nc in %!ic! #t$rt -it( $22r## -1t( $c>no%l2)+nt -it( co++$n2 -1t $n2
2$t$ -1t# $r to - #nt $lon) t! I:C -.#( 'l$# r*r to t! 2$t$#!t o* D,1=:1(
%!rin t!# $#'ct# !$6 -n 8'l$in2 in 'ro'r 2t$il5 T!i# %ill !l' in
.n2r#t$n2in) t! contnt# o* t! +$in 'ro)r$+5
Microcontroller 'nit
Microcontrollr AT8"C5: 3IC:4 i# $ /0 'in IC *ro+ At+l5 It# 'in 2t$il# $r #!o%n in
t! 'in 2#cri'tion 2i$)r$+5 Li> AT8"C51( it $l#o -lon)# to t! 80;1<8051 *$+il15
Microcontrollr AT8"C5: !$# $ :5=L8 -it intrn$l r$n2o+& $cc## ++or1 3RAM4( i)!t
intrr.'t #o.rc# $n2 80B o* *l$#! ++or1 co+'$r2 to 1:8L8 &-it intrn$l RAM( #i8
intrr.'t #o.rc# $n2 /0B *l$#! ++or1 in AT8"C515 B1 co+-inin) $ 6r#$til 8&-it
CPU %it! *l$#! ++or1 on $ +onolit!ic c!i'( At+l AT8"C5: i# $ 'o%r*.l( !i)!l1 co#t&
**cti6 #ol.tion to +$n1 +-222 control $''lic$tion#5 Port# 0 $n2 : $r 8&-it
-i2irction$l in'.t< o.t'.t 3I<O4 'ort#5 T!# 'ort# !$6nNt -n .#2 in t!i# t+'r$t.r
in2ic$tor5 Port 1 i# $n 8&-it -i2irction$l I<O 'ort %it! intrn$l '.ll&.'#5 Port# 150 t!ro.)!
15G $r connct2 to 'in# G t!ro.)! 1/ o* t! LCD5 Port 1 o.t'.t -.**r# c$n #in>< #o.rc
*o.r TTl in'.t#5 Port ; i# $ 8&-it -i2irction$l I<O 'ort %it! intrn$l '.ll&.'#5 Port# ;50
$n2 ;51 o* IC: $r connct2 to #ri$l cloc> lin 3,CL4 $n2 #ri$l 2$t$ lin 3,DA4 o* IC;(
r#'cti6l15 Port ; o.t'.t -.**r# c$n #in><#o.rc *o.r TTL in'.t#5 A 1:MH? cr1#t$l
o#cill$tor i# connct2 to CTAL1 $n2 CTAL: 'in# *or o'r$tion o* t! +icrocontrollr5 A
!i)! '.l# on R,T 'in 3'in "4 %!il t! o#cill$tor i# r.nnin) r#t# t! +icrocontrollr5 In
t!i# circ.it( t!i# 'in i# connct2 to SVcc t!ro.)! c$'$citor# C5 310.F( 1=V45 T!
8trn$l&$cc## n$-l 'in 3EA4 i# connct2 to SVcc *or intrn$l 'ro)r$+ 8c.tion#5
T!i# 'in $l#o rci6# t! 1:V 'ro)r$++in) n$-l 6olt$) 3V''4 2.rin) *l$#!
'ro)r$++in) %!n 1:V 'ro)r$+ i# #lct2
TEST7NB
Visuali<ation Test9
B!n t! *$-ric$tion 'roc## i# co+'lt2 U $ll t! co+'onnt# !$6 -n +o.nt2
'r*ctl1 t! 6i#.$li?$tion t#tin) i# 'r*or+25 In t!i# t#tin) t! circ.it i# #c$nn2
#i+'l1 -1 t! 1# U not -1 t! !l' o* $n1 in#tr.+nt5 It to n#.r t!$t t! #ol2rin) i#
'r*ct $n2 t!r i# no loo# connction -t%n t! co+'onnt#5
)re4heatin0 Test1
T!i# t#t i# 'r*or+2 to c!c> t! !$t tolr$nc o* t! co+'onnt#5 In t!i# t! circ.it i#
'ro6i22 'o%r #.''l1 $n2 l*t *or #o+ ti+5 A*tr $ intr6$l o* ti+ it i# c!c>2 t!$t i*
t!r i# $n1 co+'onnt )t *$.lt1 co+'onnt #'ci$ll1 *or IC7#5
A..lications1
15 T!i# #1#t+ c$n - 'l$c2 n$r co+'.tr 'roc##or# *or !$t #n#in)5
:5 Pl$c2 n$r !$t #n#iti6 26ic# to in2ic$t t! t+'r$t.r5
;5 T!i# #1#t+ c$n intr*$c2 %it! co+'.tr# $n2 t+'r$t.r c$n - controll25
PCB Layout:
#$%&$A' in Assem(ly:

;program for the automatic temperature Controller
;Cetpa-Roorkee
; matirx keyboard with connections on p2 port
;rows are connected to p2.0 to p2.2
;columns are connected to p2.4 to p2.7
;Lcd connected at p1 with Controls pins
; at rs-p3.5,rw-p3.4,en-p3.3
sda equ p0.1
scl equ p0.0
rs equ p3.5
rw equ p3.4
en equ p3.3
lcd equ p1
lcd_busy equ p1.7
key_brd equ p2
th equ 50h
tl equ 51h
ascii_store equ 40h
delimiter equ 20h
delay_count equ 23h
temperature_store equ 30h
temp_result equ 35h
LCD_str equ 2ah

;Flags
th_fag equ 7fh
tl_fag equ 7eh
temp_fag equ 7dh
org 0000h
mov sp,#60h
lcall ini
clr th_fag
clr tl_fag
mov th,#40
mov tl,#37
mov dptr,#Msg0
acall msg_read
mov delay_count,#40 ;for 2-sec time
acall time ; $$$$$$$$$$$$$$$
value_enter:
mov r7,#01h
acall command
mov dptr,#Msg1 ;show th
acall read
mov a,th
mov r1,#LCD_str
acall bin2ascii
inc r1
acall tim_display

mov r7,#87H
acall command
mov dptr,#Msg2 ;show th
acall read
mov a,tl
mov r1,#LCD_str
acall bin2ascii
inc r1
acall tim_display
;till here default values are shown
;into nezt line show following
mov r7,#0c0h
acall command
mov dptr,#Msg5
acall msg_read
scan0:
mov key_brd,#0f0h ;bcoz upper 4
mov a,key_brd ;are connected to colu
cjne a,#0f0h,mode_check0
sjmp scan0
;**************** detecting rows
mode_check0:
acall delay1
mov a,key_brd
cjne a,#0f0h,mode_check1
sjmp scan0
mode_check1:
acall delay
acall delay1
mov key_brd,#0fh
mov key_brd,#0fbh
mov a,key_brd
cjne a,#0fbh,enter_check
ajmp scan0

enter_check: ;This is enter button
jb acc.6,mod43
ajmp temp_conversion_start
ljmp scan0
mod43: ;This is clear button
jnb acc.7,clear_press
ljmp scan0
clear_press:
mov r7,#01h
acall command
mov dptr,#Msg1 ;show th
acall read
mov r7,#38h
acall command
mov r7,#0eh
acall command
mov r7,#06h
acall command
mov r7,#0c0h
acall command
setb th_fag
; mov r6,#3
ajmp forward
tl_edit:
mov r7,#01h
acall command
mov dptr,#Msg2 ;show tl
acall read
mov r7,#0c0h
acall command
setb tl_fag

forward:
mov lcd,#00h
scan:
mov key_brd,#0f0h ;bcoz upper 4 are
mov a,key_brd ;connected to column
cjne a,#0f0h,row
sjmp scan
;*************** detecting rows
row:
acall delay1
mov a,key_brd
cjne a,#0f0h,row111
sjmp scan
row111:
acall delay
acall delay1
mov key_brd,#0fh
mov key_brd,#11111110b
mov a,key_brd
orl a,#0fh
cjne a,#0fh,row1
mov key_brd,#0fh
mov key_brd,#0fdh
mov a,key_brd
cjne a,#0fdh,row2
mov key_brd,#0fh
mov key_brd,#0fbh
mov a,key_brd
cjne a,#0fbh,row3
ajmp scan

;**********
row1:
jb acc.4,c2
mov r7,#'0'
acall display
sjmp scan
c2:
jb acc.5,c3
mov r7,#'1'
acall display
sjmp scan
c3:
jb acc.6,c4
mov r7,#'2'
acall display
sjmp scan
c4:
mov r7,#'3'
acall display
sjmp scan
;****************
row2:
jb acc.4,c22
mov r7,#'4'
acall display
ljmp scan
c22:
jb acc.5,c32
mov r7,#'5'
acall display
ljmp scan
c32:
jb acc.6,c42
mov r7,#'6'
acall display
ljmp scan
c42:
mov r7,#'7'
acall display
ljmp scan
;****************
row3:
jb acc.4,c23
mov r7,#'8'
acall display
ljmp scan
c23:
jb acc.5,c33
mov r7,#'9'
acall display
ljmp scan
c33:
jb acc.6,c43
ajmp test ;This is enter button
ljmp scan
c43:
;This is clear button
;not used here
ljmp scan

;*******************
test:
mov r7,#04h
acall command
acall ready
acall read_add1
clr c
mov b,#0c0h
subb a,b
mov r0,a
mov r1,#ascii_store
acall ready
acall read_data
repeat:
inc r1
acall ready
acall read_data
mov @r1,a
djnz r0,repeat
mov delimiter,r1
inc delimiter
;********
;conversion routine ;bank 1 used
setb psw.3
mov r5,#00h ;used for msb
mov r6,#00h ;used for storing the lsb result
mov r0,#0ah
mov r2,#1
mov r3,#10
mov r4,#100
mov r1,#(ascii_store+1)
here: clr a
mov a,r1
cjne a,delimiter,convert
ajmp break ; read till there
convert:
mov a,@r1
anl a,#0fh
mov b,@r0
mul ab
mov r7,a
xch a,b
cjne a,#00h,hiii
looo:
mov a,r6 ;result of add
addc a,r7
jc for
con: mov r6,a
inc r1
inc r0
ajmp here
break:
clr psw.3
;**********************
jb tl_fag,tl_save
clr c
mov a,0eh ;0eh is the add of r6 of bank1
cjne a,#7dh,th_check
th_check:
jnc error_msg ;a> or = 125 show error
mov th,0eh ;if c then save
clr th_fag
ajmp tl_edit
error_msg:
mov r7,#01h
acall command
jb tl_fag,tl_error
mov dptr,#Msg3
acall msg_read
acall time
ajmp clear_press ;again enter th
tl_error:
mov dptr,#Msg4
acall msg_read
acall time
ajmp tl_edit ;again enter tl
;***************portion of the conversion routine
hiii:
add a,r5
mov r5,a
ajmp looo
for:
inc r5
ajmp con
;**********************
tl_save:
clr c
mov a,0eh ;0eh is the add of r6 of bank2
cjne a,th,tl_check
tl_check:
jnc error_msg ;a> or = th show error
mov tl,0eh ;0eh is the add of r6 of bank2
clr tl_fag
;now we have to show the saved values on
;LCD & wait for enter to be pressed
ajmp value_enter
;___________________________
temp_conversion_start:
mov r0,#th
acall delay10
acall i2cstart
mov a,#90h
acall i2cwrite
mov a,#0ach
acall i2cwrite
acall delay10
mov a,#02h
acall i2cwrite
acall delay10
acall i2cstart
mov a,#90h
acall i2cwrite
mov a,#0a1h
acall i2cwrite
acall delay10
mov a,th ;#28h
acall i2cwrite
mov a,#00h
acall i2cwrite
acall delay10
acall i2cstart
mov a,#90h
acall i2cwrite
mov a,#0a2h
acall i2cwrite
acall delay10
mov a,tl ;#24h
acall i2cwrite
mov a,#00h
acall i2cwrite
acall delay10
acall i2cstop
clr temp_fag ;temp fag
mov r7,#01h
acall command
mov dptr,#Msg
acall read
mov temperature_store,#00h
here1:
acall temp ;temp read by this routine
jb temp_fag,EEE
setb temp_fag
mov temperature_store,a
ajmp here1
EEE:
cjne a,temperature_store,make_equal
ajmp here1
make_equal:
mov temperature_store,a
acall conversion
mov r7,#8bh
acall command
acall string
sjmp here1
; ************************
temp:
acall i2cstart
mov a,#90h
acall i2cwrite
;*****************************
mov a,#0eeh
acall i2cwrite
; start temp conversion
acall i2cstop
acall i2cstart
mov a,#90h
acall i2cwrite
mov a,#0aah
acall i2cwrite
; read last read temp
acall i2cstart
mov a,#91h
acall i2cwrite
acall i2cread
acall i2cstop
ret
i2cstart:
setb sda
acall delayone
setb scl
acall delayone
clr sda
clr scl
ret
i2cstop:
clr scl
clr sda
setb scl
acall delayone
setb sda
mov c,sda
ret
;=======================
i2cwrite:
mov r0,#08h
i2cwrite_loop:
rlc a
mov sda,c
setb scl
acall delayone
clr scl
djnz r0,i2cwrite_loop
mov c,sda
setb scl
acall delayone
clr scl
ret
;=======================
i2cread:
mov c,sda
mov r0,#8
rlc a
i2cread_loop:
setb scl
mov c,sda
rlc a
acall delayone
clr scl
djnz r0,i2cread_loop
ret
delayone:
mov r1,#100
loopa:
djnz r1,loopa
ret
;**********************

read_data: ;data is stored in the r0 register
mov lcd,#0fh
setb rs ;to select data register
setb rw
clr en
setb en
mov a,lcd
clr en
ret
read_add1:
mov lcd,#0fh
clr rs
setb rw
clr en
setb en
mov a,lcd
clr en
orl a,#80h
ret
read_add:
push acc
mov lcd,#0fh
clr rs
setb rw
clr en
setb en
mov a,lcd
clr en
orl a,#80h
cjne a,#8fh,out
mov r7,#0c0h
acall command
out:
pop acc
ret
;******************
conversion:
push acc
mov a,temperature_store
mov r0,#(temperature_store+1)
conloop:
mov b,#10
div ab
orl 0f0h,#30h
mov @r0,0f0h
inc r0
cjne a,#00h,conloop
dec r0
mov r1,#temp_result;35h
conloop1:
mov a,@r0
mov @r1,a
dec r0
inc r1
cjne r0,#temperature_store,conloop1
mov @r1,#'$'
pop acc
ret
;====================
string:
push acc
mov r0,#temp_result;30h
strloop:
mov a,@r0
mov r7,a
cjne a,#'$',continue
mov r7,#' '
acall display
pop acc
ret
continue:
acall display
inc r0
sjmp strloop
;*******************
bin2ascii:
mov @r1,#'$'
dec r1
rep:
mov b,#10
div ab
orl 0f0h,#30h
mov @r1,0f0h
dec r1
cjne a,#00h,rep
ret
tim_display:
brij: mov 07h,@r1
cjne r7,#'$',shoe
ret
shoe:
acall display
inc r1
ajmp brij

command:
acall ready
mov lcd,r7
clr rs
clr rw
setb en
clr en
ret
display:
acall ready
mov lcd,r7
setb rs
clr rw
setb en
clr en
ret
ready:
clr en
mov lcd,#0fh
clr rs
setb rw
wait:
clr en
setb en
jb lcd_busy,wait
clr en
ret
ini:
mov r7,#38h
acall delay1
acall delay1
acall command
mov r7,#38h
acall delay1
acall command
mov r7,#38h
acall delay1
acall command
mov r7,#0eh
acall command
mov r7,#01h
acall command
mov r7,#06h
acall command
mov r7,#80h
acall command
ret
delay10:
push acc
mov tmod,#01h
mov tl0,#10h
mov th0,#27h ;1050=2710h
mov tcon,#00h
setb tr0
wait12: jnb tf0,wait12
clr tr0
pop acc
ret
delay1:
push 07h
push 06h
mov r6,#100
loop24: mov r7,#100
loop23: djnz r7,loop23
djnz r6,loop24
pop 06h
pop 07h
ret
;**********
delay:
push acc
push 00h
mov r0,#02h
loopr:
mov b,#0a0h
loopb:
mov a,#0fah
loopa12:
dec a
jnz loopa12
djnz 0f0h,loopb
djnz r0,loopr
pop 00h
pop acc
ret
time:
push 00h
mov r0,30h ;30h contain counter
mov tmod,#01h
repeat1: mov tcon,#00h
mov th0,#3ch
mov tl0,#0aah
setb tr0
wait1: jnb tf0,wait1
clr tr0
djnz r0,repeat1
pop 00h
ret
msg_read:
push acc
push 07h
nex: clr a
movc a,@a+dptr
mov r7,a ;r7 is used for passing parameter to display
cjne a,#'0',aga
sjmp down
aga: acall read_add
acall display
inc dptr
sjmp nex
down:
pop 07h
pop acc
ret

read:
nex1:
clr a
movc a,@a+dptr
cjne a,#'0',aga1
sjmp down1
aga1:
mov r7,a
acall display
acall delay1
inc dptr
sjmp nex1
down1:
ret
Msg: db 'Temprature ','0'
Msg0: db 'Welcome To Auto Temp Controller','0'
Msg1: db 'TH ','0'
Msg2: db 'Tl ','0'
Msg3: db 'Error: TH > or = 125','0'
Msg4: db 'Error: Tl > or = TH','0'
Msg5: db 'Enter for cont.','0'
end



; mov r7,#'4'
; acall display
; mov r7,#'0'
; acall display
; mov r7,#87h
; acall command
; mov dptr,#Msg2 ;show tl=
; acall read
; mov r7,#'3'
; acall display
; mov r7,#'7'
; acall display
;================ End Of Program Code =====================
Co&ponent>s List +or Pro?ect
AT8"C51 1
D,&1=:1 1
: Lin LCD 1
B.??r 1
Tr$n#i#tor BC 5/8 1
LED 1
R#i#t$nc# 100 5
R#i#t$nc /G0 o!+ 5
;;'ico*$r$2 Cr$+ic Di#> C$'$citor :
Cr1#t$l O#ci5 31: MH?4 1
Mini ,%itc! 1;
100 Pot 3Pr#t4 1
Dio2 1n/00G /
IC B$# 38Pin( /0Pin4 1 $c!
Rli+$t 35 'in $n2 : 'in4 1 $c!
Rli+$t 31='in4 :
Po%r c!or2 1
C$'$citor 100Micro*$r$2< :56 1
C$'$citor 10 Micro*$r$2 < :56 1
Volt$) R).l$tor IC G805 1
Tr$n#*or+r 3"&0&"4 1