华南理工大学数字系统设计全英试题A卷Word格式文档下载.docx
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C.BIT;
D.ARRAY
3.WhichofthefollowingstatementsonPLDisnottrue(B)
A.CycloneIIisproducedbyAlteraB.FPGAisbasedonproductterms
C.FPGAisfieldprogrammablegatearray
4.Whichofthefollowingstatementsonsequentialcircuitistrue(B)
A.Insynchronouscircuit,theactionsofFlip-Flopsarenotnecessarilysynchronizedbythesameclocksignal
B.Inasynchronouscircuit,thestatesofFlip-Flopsdon’tchangesimultaneously
C.TheinputchangeofMoorestatemachineisdirectlyreflectedbyoutput
5.Whichofthefollowingstatementsonstatemachinedescriptionisnottrue(C)
A.Inone-processdescriptionstyle,outputcanbesynchronized
B.Two-processdescriptionstylecanavoidunwantedregisters
C.Two-processdescriptionstyleconsumesmoreresourcesthanone-processdescription
6.Whichofthefollowingstatementsonmetastabilityistrue(B)
A.Insequentialcircuit,metastabilitydoesn’toccurifeithertheset-uptimerequirementortheholdingtimerequirementismet.
B.Metastabilitydoesn’tnegativelyimpactthesystemifthemetastableoutputresolvestothenormalstatebeforeitiscapturedbythenextregister.
C.Metastabilityusuallyoccursinsynchronouscircuit.
7.WhichofthefollowingstatementsonVHDLsignalisnottrue(C)
A.VHDLsignalisusuallysynthesizedasnodeorwire.
B.InVHDLentity,portisconsideredassignalbydefault
C.Assignmenttothesamesignalindifferentprocessescanbesynthesized,butonlyonesignalassignmenttakeseffect.
8.Forstateencodinginstatemachine,whichofthefollowingschemeismoresimplefordecodingatthepricesofmoreFlip-Flopsinencoding:
(A)
A.onehotcodeB.NaturalbinarycodeC.Graycode
9.WhichofthefollowingstatementsonVHDLcasestatementisnottrue(B)
A.Eachbranchofcasestatementshouldbecorrespondingtooneorseveralpossiblevaluesoftheevaluatedexpression.
B.Statement“WHENOTHERS=>
NULL”mustbeincludedincasestatement
C.Inexecutionofcasestatement,onlyonebranchisselected
10.Whichofthefollowingstatementsisnotconcurrent?
(B)
A.processstatementB.CASEstatement
C.componentinstantiationD.WHEN…ELSE…statement
2.Shortanswerquestions(5ⅹ4=20marks)
1、PleasespecifythebasiccomponentsofASMchart,particularly,explainwhatastateis.
BasiccomponentsofASMchart:
statebox,decisionbox,andconditionaloutputbox.
Onestateismorethanastatebox,conditionaloutputbox,ordecisionboxcanalsobeapartofthestate.Astaterepresentsthesystemstateduringoneclockcycle,indicatingtheoperationstobedoneinthestate.
2、Whatisthedifferencebetweensequentiallogiccircuitandcombinationallogiccircuit?
Combinationalcircuit:
changesininputsareimmediatelyreflectedbychangesinoutput.Thestableoutputdependsonthecurrentinputonly.
Theoutputsofasystemdependonpastvaluesofitsinputsaswellasthepresentstatevalues.(dependonbothpresentstateandhistorystate)
3、Pleasespecifythebasicstructureofsequentiallogiccircuit
Structure:
itiscomposedofcombinationallogicgates,andmemorycomponentssuchasFlip-flop,registers.
4、Pleasedescribetheconceptofset-uptimeandholdingtime.
Setuptime:
Toensurereliableoperation,theinputtoaregistermustbestableforaminimumtimebeforetheclockedge(registersetuptimeortSU).ifthetimeisnotlongenough,reliableoperationcannotbeguaranteed.
Holdtime:
Toensurereliableoperation,theinputtoaregistermustbestableforaminimumtimeaftertheclockedge(registerholdtimeortH).ifthetimeisnotlongenough,reliableoperationcannotbeguaranteed.
3、Comprehension&
design(60marks)
1、UsingVHDL,Pleasedescribeatri-statemultiplexer(MUX)accordingtothefollowingrequirements:
(10marks)
input
output
oe
a
b
sel
y
1
-
‘Z’
LIBRARYIEEE;
USEIEEE.std_logic_1164.ALL;
ENTITYMUXIS
PORT(oe,a,b,sel:
instd_logic;
y:
outstd_logic);
ENDMUX;
ARCHITECTUREBEHAVOFMUXIS
BEGIN
PROCESS(oe,a,b,sel)
Ifoe=’1’then
ifsel=’0’then
y<
=a;
else
=b;
endif;
=’Z’;
ENDPROCESS:
ENDARCHITECTURE;
2、Asapartoftestbench,pleasedescribethefollowingstimuli(6marks)
…
SignalS1:
std_logic;
SignalS2:
Process
Begin
S1<
=’0’;
Waitfor10ns;
=’1’;
Waitfor5ns;
Endprocess;
Waitfor15ns;
3、PleasedrawtheRTLdiagramforthefollowingVHDLcodes(5marks)
entityvar_sigis
port(data:
inbit_vector(1downto0);
clk:
inbit;
z:
outbit);
constantk1:
bit_vector:
=“01”;
constantk2:
=“10”;
endvar_sig;
architectureAofvar_sigis
begin
var:
process
variablea1,a2:
bit_vector(1downto0);
variablea3:
bit;
begin
waituntilclk=‘1’andclk’event;
a1:
=dataandk1;
a2:
=dataandk2;
a3:
=a1(0)ora2
(1);
z<
=a3;
endprocessvar;
endA
4、PleasecompletethewaveformsaccordingtothefollowingVHDLcodes(6marks)
Libraryieee;
Useieee.std_logic_1164.all;
EntityD_latchis
port(D,Enable:
instd_logic;
Q1,Q2:
outstd_logic);
EndD_latch;
ArchitecturebehavofD_latchis
process(D,Enable)
if(Enable=‘1’)thenQ1<
=D;
endif;
endprocess;
process(Enable)
if(Enable=‘1’)thenQ2<
Endbehav;
5、Designa4-bitALU(ArithmeticLogicUnit),whichcancompletethefollowingoperationson4-bitinputsaandb:
1)
Mode1:
Addition(a+b)
Mode2:
OR(aorb)
Mode3:
AND(aandb)
Mode4:
XOR(axorb)
2)TheworkingmodeoftheALUdependsonthemodeinputM0andM1.Forexample:
M0M1
MODE
00
addition
01
OR
10
AND
11
XOR
3)Theadditionoperationshouldhavecarried-inbitandcarried-outbit
Questions:
(13marks)
1.PleaseindicatetheinputsandoutputsoftheALU
Inputs:
a,b,M0,M1,ci
Ouput:
s,co
2.PleasefinishVHDLdesignofALU,includingentityandarchitecturedescription.
libraryieee;
useieee.std_logic_1164.all;
useieee.std_logic_unsigned.all;
EntityALUis
port(a,b:
instd_logic_vector(3downto0);
m0,m1,ci:
instd_logic;
s:
outstd_logic_vector(3downto0);
co:
);
endALU;
architecturebehavofALUis
signalmode:
std_logic_vector(1downto0);
mode<
=m1&
m0;
process
variabletemp1,temp2,temp3:
std_logic_vector(4downto0);
begin
ifmode=”00”then
temp1:
=0&
a;
temp2:
b;
temp3:
=temp1+temp2+ci;
co=temp3(4);
s<
=temp3(3downto0);
elsifmode=”01”then
=aorb;
elsifmode=”10”then
=aandb;
elsifmode=”11”then
=axorb;
=”ZZZZ”;
co<
endprocess;
endarchitecture;
6.Pleasereadeachpieceofthefollowingcodescarefully.Doeseachofthemhavethesamecircuitbehaviorlikethefollowingcircuitdiagram?
Ifno,pleasegivethereasons.(9marks)
(a)
process
waituntilrising_edge(clk);
d<
=notc;
c<
=aandb;
(b)
c1<
c2<
=notc1;
=c2;
(c)
process(c1)
(a)yes:
(b)no:
extraregisterisintroduced.
(c)yes
7、Designaserialdatatransmitter(串行数据发送器)。
Paralleldatainput‘Z’of8bitsisloadedfirstlyinthetransmitter,andseriallytransmittedthroughport‘X’.Thedetailedrequirementsarelistedasfollows:
a)Inputsignal‘load’isusedforparalleldataloading.Ifload=’1’,paralleldatainput‘Z’isloadedintheserialtransmitter,andoutputsignal‘empty’=’0’toturnofftheLED;
b)Leastsignificantbit(最低位)istransmittedfirstly;
c)Astartbitoflogic‘0’(起始位0)istransmittedfirstlybeforethe8-bitrealdatatransmission;
d)Aparitybit(奇偶效验位)andstopbitoflogic‘1’(停止位1)aretransmittedafterthe8–bitrealdatatransmission;
e)Afterthetransmissionofthestopbit,outputsignal‘empty’=’1’toturnontheLED;
Question:
(11marks)
1.Pleasespecifytheportinformation.
Input:
Output:
2.PleasedrawanASMchartfortheserialtransmitter.