Điện Tử - Cơ Sở Thiết Kế Mạch - Design Trên Máy Tính (Phân 2) part 5 doc

Dtle t,i
thea
vi tri :
m6i
philn tti
nll~n
gi,\ tri ella cluing
trong
bicu thue
then
trM
tt!.
vr
ell.).
nhu
tren
tru
phcp
gan
eu6i :
type
CoIOl'_list is ( Red, Orange. nIue.
White
);
type
Colocarray
is
array
(CoJoclist)
of
BlT_ VECTOR ( 1

downto
0);
variable
X ;
Coiocarray;
X
;=
(
"00"
.
"10"
,
"0
I"
,
"11"
);
K hi
gan
giii tf!
eho
nhom.
ta
e()
the'
kh6ng
can
thiet
(t~lt
gia

trj
eho
tAl
dl
de
ph:in
tu
ella
nhom.
Vi
dl,l.
subtype
BV7 is I3IT _
VEcrOR
( 7
duwntu
0
);
variable
X : BV7;
X:=
('0'.
'0'. '0'.
'I'.
'I'. 'I'. 'I'.
'1');
X '.= ( '0' . '0' . '0' . others =>
'1'
);
X

:=
llvT ( '0' • '0' . '0' . others =>
'I'
):
g, Cae hien
thue
djnh
kieu
Oie
bieu
thuc
djnh
kicu la !lhiing bi2u thue
hO(IC
nh6m
ciLlIlg
de
xac
djnh
fa
nilling
tlnh
tr'.U1g
m~lp
mo.
Vi
d!.J.
nhu
trong
truong

hQ'p
hai
beu
li¢t k6 co
nhling
gia
tfj li¢t
ke
gi6ng
nhau.
CU
phapcua
bieu
thCre
dinh
kieu
nhu
sau:
hi/If
flll(e
phili
co
kieu trung. vai fl'J/):.ii;'If.
170
VI
dl,l.
tmng
truang
hqp
hai li¢t

kc
co
nhOng
gia
tri giong nhau.
type
Color{ is (
Red.
Orange,
Yellmv,
Green,
Blue. Purple);
type
Color2
is (
Green,
Black.
White.
Yellow);
variahle
X:
CaIOl·I;
X
:::::
Color!'
(
Yellow);
Uia
tri 'YeUO\v'
dU(jc

XdC djnh tuong minh
la
thut)c kicu
Colorl.
Nhu
v(ty phcp gall (r2n lit dung \'6i cu
phap.
h.
Phcp
ehuycn
dui
kicu
Phep
ehuycn
u61
kicu
cung
dip
phuong ti¢n
biC'n
(k~i
gia
tq
ella nht1ng
doi
tU<;l'ng
Ihw>e
nhGng kieu
e6
quan

h~
eh~t
ehe
voi nhau \'i dy nille kieu
rca
I
va kieu intej:!,cr.
CU
ph,ip ella
ph~p
bien doi kieu
nhu
"au:
VI
tiy,
signal
X:
STD_LOGIC_
VELIOR
(
~
downto
0);
signal
Y:
STD_ULOUIC
YECrOR
( 3 down to
0):
Y

<=
STD_ULOGIC
YECroR
( X
):
~6.5.
Cae
e:lu
true
tmln
t~
Trang
ngon ngfr VIIDL, kie'n true Xil.c djnh eh6e
nfmg
ella timc
the:.
Trong
kicn true
chua
ph[in khai
IXlo
cae
ki~u,
d.e
I[n
hi2u. cae
htll1g.
dc
thanh ph[in va
de

chlfo'ng trinh con.
111(.:0
sau
phAn
khili bao li\
eAc
C{lll
Irllc
tlu.re
hi¢n dong thoi.
Cic
eau
true thlfe
bi~n
dong
thai
co
the:
iit
de
bi0u tbue
gall tin
hi~u
song song.
de
khoi
\'a
cae
!<;nh
kll{1i

tao phien ban
cUJ.
Ihanh
phfin.
Cae
I~nh
thy"e
hi~n
dong thai
dU~1e
ket noi
veti
nhau hang
nhG'ng
I[n
hi~u.
Moi
khoi
ICnh
tiwc
hi~n
dong thai trong mt)t kit'n true xac dinh
In91
don
yj
t[nh toan
baD
gOIl1
de
thao t,le tfnh toan nhu:

dQe
tin hi¢u \,ao. tlwc
hi~1l
de
tfnh toan trcn cue lin
hi~u
do
va gan nhnng gia Iri tfnh
dUQ'C
cho
de
tin
hi~u
ra.
Trang
ngon
ngt1
VHDL,
I1H?t
cau
true
thy"e
hi~n
d6ng
thoi
II
qua
trlnh
(
pruees "

).
Qua
tdnh
Iii.
lTIt)t
du
true
quan
trQng
dV(je
su
tlL.IIl);
de
m6
1:1
171
hill1h
vi
hOi 11
dong
cua
mi LCh.
Trong
ITIQI
kien lr(lc,
1[\1
ci
dc
qu,\ trlnh sl'
dW1C

Ih~rc
hi¢n d6ng thai khi
ma
phung.
\11)1
qu,\ trlnh
duC)'c
xay
dl!ng
tll"
nhl1ng
cfiu
Ink
lu,"in
IV
- hay
6lJl
~t)i
Iii
c,le \¢nh tufin
tlr
Trong thoi gian
ITIO
phlmg, cac
\~nh
IU(1Il
IV
Irong
]lll)1
qll'.\

trinh sc ctuae
tlll.rc
hi¢n
\fill
IUQ1
trong
1l1(1\
chu trinh
VO
\wn
hM
dfill
Ill"
I~nh
thCr
nh:it
(k"n
10:nh
lhu
/I
va sau
do
vi¢c thvc
hi~n
qua trlnh
1<.li
quay
In)"
t.li
knh

cti.lu.
Vi¢c Ilwc
hi~n
Il1Ql
qua Irlnh trong qu,i trlnh m6 phlmg
In~n
ngon
ngiJ
VHDL
hi
dung
h.li
khi
gZtp
diu
l~nh
wait
va
duC)'c
kfeh hoat
I' Ii
khi
c()
su
thay
cit),
tn.Lng
thai eua it
nh[it
tnQt

trong
cac tin
hi~u
mCuTI
Irong
danh
sitch
die
till hi¢u
I(IC
d(mg.
Cac I¢nh
ttHIn
IV
trang ngon
ngCr
VIIDL gum eo:
Gill
\¢nh gan eho hien;
Gill
I¢nh gan cho lin hi¢u;
Cau I¢nh
iF;
Gill
1¢1111
case;
Gill
I~nh
rcng
null:

Cic
I¢nh \'()ng
\(tp.
1.
Phcp gan bien
Trang ngon
ngu:
VIIDL, phep gan bien co lac
d~lllg
\u"lmg
II!
phcp gan
().
cae ngon
ngil"
1(lp
Irlnh truyen thong. Phcp g •
.in
bien
IhleL
\(\p g[,\
tr!
m6"i
cho
hilYn.
Cu.
ph<lp
cua phep gan bien
nhu
sau:

bit';11
:=
hilll
tllli't":
Ve"
tnti eua phep gan
phil!
la
bien da
dUQ'c
khai
bilo
tir truac.
Ve
ph,ii ella
phcp gan
Ia
bieu thuc.
De
phcp gan co the tlwc hi¢n duqc, bieu thuc d
\'C
trai
va
bien
ave
pil,ii
clLa
phep gan phai cung
ki6u,
Klli

mc)t
bien
dU"qc
gan gia
II'"
phcp gan duqc
Ihl:re
hi¢11
vl:ii
tl1(\i
gLan
rno
phimg
bimg.
khong.
DieLl
d6 e6 nghia IiI sl! Ihay do, gia tri
cua
bien
ctuqc
xu)'
ra
ttk
Iho-i
ngay
t:'.li
thui diem
rna
ph6ng hi¢n tai.
Cac

hic'n
chi
dU"<;1c
khai bao trong cae gu

!.
trlnh
ho<:tc
ChU0Jlg
trlnh con
va
duC)'c
slr
cl~l!1g
de
Iuu
tnl cac ket qua trung gian. M¢t bien
dU"q'c
khai
[)iio
hl':n
trung m(ll qua
tdnh
hO(lc
chuang trlnh con se ton
t~li
C~IC
bl)
lrang qua trlnh
ho~tc

chuong
lrlnh
con do
va
kh6ng the
dU"<;1C
truy
C~tP
16i
Ilr
cae
e~iu
truc
:->ong
song
kh

"ic.
172
VI
dV
ph{;p
gan bien,
suht."pe
Intl6
is
integcr
rallj!;c 0
to
05635;

siglwl S1.
S2;
In116:
si~nal
(iT:
boolean:
pruccss
(Sl,
S2)
variable
A,
13
: Int16:
COllstant
C:
Intlo;=
100;
bcgin
A
:~Sl
+ I:
B
:~
52 *2 -
C:
GT <= A >
13;
end
pl'ocess;
2.

Phep
gall tin hieu
Trong ngon
ngi::i'
V HDL. tin hi¢u
lA
m9t
d~ng
clui
tuVng
d[\c
bi¢t.
Ph{;p
gan tin
hi~u
dung
de
tbay doi gia
tri
eua tin hi¢u. Die tin hi¢u lu6n
c1uo'C
bi~u
dicn
kc't
hQ'p
v6i dicn
biC:n
thui gian. Phcp gan tin hi¢u thay doi
gi{\
II'!

clla lin
hi~u
tl(ang lrng thea thui gian va plw
thu<)e
vao
de
mo hlnh qua Irlllh Ire
Irong
d.e
phfin
Ill'
mi leh.
Khi tin hi¢u
citlqe
gan gia Ir!. gia
Ir!
m6i
clo
kh(ing
dWK
g.an
\"()'j
1111
hl~U
m()\
deh
IU."C
Ih,1i
mil.
plliii sau

11191
thoi gian
duq'c
d~nh
Ijeh lrlnh trude trong
Iho'i
diel1l
m6 ph6ng tiep then
wang
lWg
v6i
1110
hlnh
tre. Phep gall lin
hi~u
eo
eu
ph{lp
nhLf
sau:
fJ/c"II_lfllk xJc djnh
dlc
gia tri gall. Kieu clla bu;'u_,IIII"c
ph"li
trung
\'6'j
ki~ll
ella
1{/I)li~;II_,1fc".
IfuJi_Ulal/

iii.
bieu thlIe C() kieu
TIME.
Trang
1119t
qu,i trinh, vi¢c gan gia Iri clla
bi~u
thu'c
cho tin
hi~u
sc
throc
lam tre
khi chu trinh mo ph6ng
diUlg
thlfc
hl~n
va
dUQ"c
kiem
soit
bo-i
loan
Ilr
wait. Chlmg ta hay xct
VI
d~l
ve
phep gan tin
hi~u

trang
dOi U1
chuC1ng
I["[nh
sau:
proccss
hc~in
end;
S 1
<:::::
nut
eLK
after
30
ns
;
Sl
<= DIn
aftcr
0 ns ;
S3<=SllmdS2;
wait
on
eLK;
Trang doc.lrl chuang Irinh nay. Ihao
tac
g.ln
kc'l
qua
c.:ua

phcp
tO<Ill
"not
eLK"
cho
bien
SI
'iC
chI9c
I1wc
hi91l
~au
30
ns
tlnh
IU
tho'j
di~m
Illt)
phong hien lai.
Trong
Call
\¢nh Ihtt hai. thai gian tre
clli.l
phcp
g<.in
dU"(fc
clio Ix\ng
'0',
khi

do
n¢c
gtlll
gi,i
Iri
ella
lin hi¢u DIn
cho
tin hi¢u S2 s0
du"(1C
tln.!"c
hi¢li
sau
khaang
thi:1i
gian delta tlnh
III
th(:ji
diem
m6
phc'mg
hl~n
t'.lI.
Tm111g
!L.r
nlllr
v;ly.
t!"ong
ph 'p
g.,in

lIn hieu
1\111
ta.
kct
qu<.i
ella
phc'p
tOiln
IC)gic
and
\11lK
hi¢n Ir0n cac gia tri hi¢n
tho'i
cua lill hi¢u SI d S2
Sl:
dlf0c gan cho tin hi¢u
Sl
S,tU khming
tho'j
ginn delta tinh
IV
Ihui
diem
1116
ph()ng hi¢n
Ih('ii.
Khi
XU<lt
hi¢n
st!

ki~n
tren
dU'ung
lin hi¢u
eLK
( gi,i tri
tn~n
duang tin hi9u
eLK
chuycn
tLr
'0'
sang
'I'
),
tat
d.
cac giaa
d~ch
<.tJ
dU(Jc
dillh lich trlnh Inf(k
thai di6m
Xuflt
hi~n
slf ki¢n sc
dUQ"c
tlwc hi¢n b6i
h0
m()

ph()ng.
Khi tin
hl¢U
dl:qc gan
gi,,\,
Ir!
trang qua trinh, phcp
g{m
s2
:.;.{tC
dinh m6t
h<,1
dieu
khien lin hi¢ll. Trang
me)t
qua trinh,
I110t
tIll
hl~U
chi co
the'
nl
1n01
clicll khien, dicu d6 co nghlu
Ib.
ben {rang
lllQt
qua trlnh tin
hi~Ll
chi e6

Ih~
xu[it phat til
me>1
ngu()ll. Neu tin
hi~u
dU<;1c
gan
gi{1
II"!
trong nhicu qua
tl"lnh

h;lc
!lhau, cllling ta
1161
l"t'ing
tin
hi~u
c6 nhi6u dieu
khi~ll.
Trong
ng{)n
ngu'
VIIDL,
lrong
true\ng
lWp
m()t
lin hi¢u c6 nhicu dicu .klllen, cae
h~l1n

lJu),ct
d~nh
duc.K
xily
dl;rng
c1~
xac d!llh gia tri cae tin
hl~U
eo
llhiC:u
cilCLl
khic;n
J"\hu'
(1;1
de
e<\p
ltii Irong
c!lll"ong
ha,
Irong
lhl~1
! c'
m'lch.
ChLlllg
la
ph~11l
bi~1
bai
h<li
d:'.l1lg

thai gian
In':
khi
ta
dicu khien
d.c
Ihao
t,IC
Ircn
Illl
11I¢u
thc()
Ihi\i
gian:
IhCii
gian Ire qu,in tfnh
\"it
Ih('ii
gi':'lIl
Ir(:
Ian
Iru)-'"cn.
174
Thll'i gian
tr~
quan
11nh
(hwc the hi¢n
m[tC
djnh

lrung ng()n
ngCr
VHDL.
GlCt
II"~
thi:1i
gJan
tn~
qU{ll1linh
lit
dt)
dili
gitii han
dn
Ihi(,'1
u'la
tin hicu
tAc
dong
d~
thiet c6
Ih~
ph,'tn
(rng
vc1i
sV
xufit
hi~n
Ifn
hi¢u

d[iu vao. Neu thai
gian
16n
I,.ti
cua tin hi¢u
dfiu
\'ao khong
\"lI01
qua
gij
trj
thl:fi
gian
In!
qu;in tlnh thi
lTIi lch
sc kh6ng phan
lJng
v()'i
s~r
Ihay
dOl
ella tin hi¢u. Th()ng s6 thai gian
Ir~
qu,in tinh
dU'<;1c
sU:
dl;lllg
lrang
quS trinh

1116
hinh hoa cac thiet
bi
so
d~
loal Irir
s~r
xu[.t
hi91l
nhOng
xung
11hon
\'.li
dflU
\,~IO.
Thdi
gian
tre Ian
truycn
Ja
thai
gian
In'S
xual hien khi tin hi¢u di qlla
ll1'.Kh.
TiI
khoa
transpOI't
dV<,"ic
dung

lrong
twang
hQ"p
thai
gian
11\':
lrong
phcp
g<ln
lu
tho-i
gian
Ir~
Ian
truy~n.
Neu
khong
slr dl,lng tiI khoa
transport
trong
phcp gall tin hi¢u.
thai
gian tre se
dVQ"c
coi
lil.
thai
gian tre qUiln tinh 1l1()\
each
null

d\llh.
Vi~c
SLr
dl,lllg tre quail I[nh
Vll
tn~
Ian
truycn
tao nen nhu·ng
hi¢u
Ling
khi\c nhau len
qUi}
trlnh
!TIO
phong. Chung
ta
hay
xct
qua
trlnh sau:
sij.!;nal
S:
BIT
::::::
'0';
prol'l'sS
hegin
S
<=

'
I'
after 5
ns
;
S <= '0'
after
10
ns:
end
process:
Trong
c:tu I¢nh
thCc
nha!.
he
thong
1110
ph6ng
se
djnh
I\ch lrillh
cho
ph':p
g(ll1
tin hi¢u S gi,.l tri 'J'
saL!
5 ns linh tir
Ih(1i
di~m

mo
phong
hi¢n
thai
D6i
\'(1i
cflu I¢nh
thCr
hai,
h¢
1116
phcmg se djnh Ijeh trlnh
eho
phcp
giil}
gli.'l
If!
'0'
eho
tin
hi~u
S sau 10 ns Ifnh tir thai
di~1TI
m6
ph6ng
hien thai.
NhLf
V(ly,
du
l¢nh

thCr
hai sc
xoa
b6
kc·t
qua
ella phep
gan
thu
nhAt
bui
VI
gi<.1.
Irj thai gian tre
1;:1
thoi
gian
tre qUiin tfnh.
GIU
I¢nh thlr nhat chi ra rtmg
thai
gim1
tre
qu<.!n
tinh
ella
phcp
gi.1.n
1;:1
5 ns, trong khi

do
cflu l¢nh tht! hai khil.ng
djnb
thai
gian
tr~
qUol[\
tinh
ella
ph~p
giin
!~I
10 ns.
I\'eu doi
cl10
hai phcp
gan
trong
ctO'.1I1
chu·ong trlnh tfen, ehllng la
nh(lI1
dU\1C
qUe!
tdnh
duoi
day,
signal
S:
BIT:=
'0':

)11'Ol'l'SS
begin
S <= '0'
after
[0
ns:
S
<=
'1'
after
5 ns :
wait
on
ClK
:
end
process:
175
Trong
trueillg
hq'p
n:t:',
du
ICnh
g<in
thu
nhat se
X,-lc
dinh
IDQI

ph~p
gan gia
tri
'0'
eho
tin
hi~u
S sau
10
ns
trnh
tu
thai di6m
IDO
ph6ng
hit;'11
thl1'i
con
phep giln th(i' hai
;.,e
:de
d!nh
thao
t<lC
gan gia
tr!
'1'
eho
S sal!
:)

ns so \'l)i
tht'J"i
(ticll1 hien
Ih{ii.
l\'hu
\,~ty.
khi h6
IDO
phong
htlt
dUll
thlfC
hi¢n,
d.c
giao
t,.i.e
eua
phcp
g<.in
thll hai
c1U<,K
t1wc
hi9n Ihay
eho
cac giao
tik
ClW
phcp
g{1ll
thll"

nhtit. Dictl do c6
nghl<l
Iii,
chi c6 phcp gan gia
tr[
'1'
cha
tin hi¢u S tal
thl1i
diem:)
ns tfnh tit thai diem
mo
phong hi¢n th0i
se
c1uQ'c
th~tc
hi¢n.
Nc'u
lrong
dOi lt1
clllwng lrinh lren. chung ta Ihay
1h0i
gli.\n
tn:
qu<ill
tfnh
bhng thoi gian tre
Ian
truyell nhu Irang
cta'.H1

clllf(1ng
trlnh duai day,
k61
qu,i
thlle
hi¢n
cua
qua Irlnh
siS
thay
dOl,
signal
S:
nIT:== '0';
process
hegin
S
<::::
transport'
l'
after:)
ns
:
S
<::::
tran!olport '0'
after
IOns;
wait
on

eLK:
end
process;
Trong do
•.
tIl
chuang trlnh nay, vi¢c gan gi,i tri '}' cho tIn
h!¢u
S
se
dlf(~C
lilm
tre
:'i
ns
tlnh tv
1h(1i
diem m6 phong. Con phep
gem
tin hi¢u
t11lt
hai se
t11f'm
m()t
thaD tae
m{1i
cho dieu khien
eua
tin
hi~u

S.
Dicu
n:1Y
co
nghla
LI
'>C
Cl)
hai
thaD
lac
cluqc
IhLJc
hien:
mot
Ihao
1.le
gall
gi<.i
Irj
x,iy
ra
,>au
:)
ns
linh til
th0i diem md phong
vii
1hao
t,k

gall
thu
hai se
du:(}c
!h~tc
hi¢n sau
10
os
linh
tLl"
thoi diem
1116
ph('mg,
Kct
qUt'\
I:t
lren du'ong tin hi¢u
Sse
XU[lt
hi~n
m()\
XUllg
h~ng
'I'
co
ell)
did:)
ns
t<~i
th(1i

dic'm:)
ns
Ilnh
Itl"
t!1('1i
die'm
hi¢1\
th('}j.
176
Trang
VI
tiL!-
dang xct
6"
In.':n.
Chlll1g
la d6i ch() hai phep g,in nhl! sau:
signal
S:
BIT
:==
'0':
process
hegin
S
<==
tnlllsport
'0'
after
lOllS:

S
<==
transport'
l'
after
5
ns
;
wait
on
eLK;
end
process: