cac lenh can thiet trong lap trinh asm

!"#$%"&$%'()(*$&+,(
(
&%$/01&2$.(&$(3-4563785(
(
(
• 3-45(7%192&+1&0%+((Microprocessor*without*Interlocked*Pipeline*Stages)*
* * *
o :;<#2&(=$ %/(> (?(#'&+,(
o (:;( %+@2 ,&+% ,(
o A",21( ,&%01&2$.,(
o 7,, +B#C'(D 2%+1&2E+,(
*
• 5',&+B(F"CC,(G$%( H0&6 I0&H0&(
( ( (
*
• 8+H%+,+.&"&2$.($G(.0B#+% ,(
( ( (
o J+K"/+12B "C((L#",+()MN(.$&"&2$.(
(
o !2&&C+<O./2".(#'&+($%/+%(
*
*
• IH+%"&2$.($G((3785((MIPS*Development*And*Runtime*Simulator)*
(
* * * *
*
*
3-45(7%1921&+1&0%+((32 *regi sters)*
( *
****$0*or*$zero** ** ‐*always*con tains*0.***
****$t0*‐*$t9*** * ‐*use*for *tem porary*storage*of*data*

****$s0*‐*$s7*** * ‐*use*to*hold*address*locations*in*mem ory**
****$a0*‐*$a3* * ‐*use*as*arguments*to *syst em*c alls*
****$v0 *and*$v1** * ‐*use*as*arguments *to*system*calls*
*
A",21(3-45(2.,&%01&2$.,(G$%(C"#(&$/"'(
(
7%2&9B +&21( L8 < &'H+N( ,&%0 1&2$.,(
"//((P&:QP&)QP&;* ****#$t 3*<‐* cont ents *of*$t1*+*contents *of*$t2*
(
"//2((P&:Q(P&)Q R* ****#$t3 *<‐*conte nts*of*$t1*+*5(
* * *
* 3+B$% '(711+,,( ,&%01&2$. ,(
( C=(( P&)QC"#+C* ** ***#*$t1*<‐*value*of*word*stored*at*memory*
* * * * * **************ad dress/location*specified*by*label((
*
* C=( P&)Q:LP,SN***********#*$t 1*<=* valu e*of*word*stored*at*memory*
* * * * * * ***ad dress*specified*by*base*ad dress*
* * * * * * **in*$s0*+*3***
****
* ,=(( P&)QC"#+C* * ***#*store*value*of*word*in*$t1*to*address/*
* * * * * *******location*in*m emory**specified *by*label%
%
* *(C=(and*,= (can* also*be*byte* or*halfword,*i.e.*C# ,*C 9Q(,#Q,9)*
* * *
* 4,+ 0/$<2.,&%01 &2$.,(
* C2((( (P&)Q(:(* ************#*$t1*<‐*3* *
* *
* C"((( P,) Q(C"# +C(***********#*$s1*<‐*address*c orresponding*to*label**
(
( B$E+QP&)QP&;* ***********#move*contents*of*$t2*to*$t1(

D2% +1&2E+,*< *tell* asse mbler*how*to*translate*program,*but*are*not*
instructions.*
*
* T&+K&(
( T@C$ #C(B"2.(
( ( Precede s*your*&+K&(,+@B+.&*(program*ins tructions),*and**
* * specifies*B"2.*as*a*globa l*symbol*(rec ogni zed*by*other**
* * files*in*a*mu lti‐fi le*projec t**
* *
T/"&"(
( Precede s*your*/"&"(,+@B+.&*(data*de clarations)*
*
(text*segment *can* come*before*data*seg men t,*or* vice* versa)*
*
( T",122((U, &%2. @V(
* * Defines* a*str ing*of*characters*(each*character*is*stored*as**
* * * a*1‐ byte*ascii*value)*
*
* T",122W(U,&%2.@V(
Defines* a*nu ll‐terminated*string*(ends*with*a*null*byte)( *
( (
( T#'&+(#SQ#)Q #;(
( ( Defines* and*initi alizes*subsequen t*bytes*in*memor y*
( (
( T9"CG(9SQ9)Q9 ;(
( ( Defines* and*initi alizes*subsequen t*hal f‐words*( 16‐bit**
* * values*–*alignment*forced*to*next*eve n*address*
*
( T=$ %/(=SQ= )Q=;(
( ( Defines* and*initi alizes*subseq uent*words*( 32‐bit*values)*

* * –*alignment *forced*to*next*word*address*(multiple *of*4)*
(
( ( T,H"1+(.(
( ( allo cates*n*bytes*of*space,*usually*initialized*to*0*
(
5X5F7! !(G0.1&2$.,( $E+%E2+=(*
( System*services*used*for*input/output*
(
J$=(&$(0,+(5X5 F7!!(,',&+B(,+%E21+,(
1.*Load*the*service*number*in*register*$v0 .*
2.*Load*argumen t*val ues,* if*an y,*in*$a0, *$a1, *or*$a2*
3.*Is sue*the*SYSCALL*instruction.*
4.*Retrieve*r etur n*values,*if*any,*from*resu lt*registers**
(
Y"#C+($G(F$BB$.C'(Z ,+/(5+%E21+,((
Service
$v0
Arguments
Result
print integer
1
$a0 = integer to print


print
string
4
$a0 = address of null-
terminated string to print

read
integer
5


$v0 contains
integer read
read
string
8
$a0=address of input buffer
$a1=max. # of chars. to read

exit (stop
execution)
10



print
character

11
$a0=character to print

read
character

12

$v0 contains
character read
open
file

13
$a0=address of null-terminated
string containing filename
$a1=flags
$a2=mode
$a0 contains
file descriptor
(- if error)
read
from file

14
$a0 = file descriptor
$a1=address of output buffer
$a2=max. # of chars to read
$a0 contains
# of chars. read
(0=EOF,- if error)
write
to file
15
$a0 = file descriptor
$a1=address of output buffer
$a2= # of chars to write
$a0 contains #

chars. written
(- if error)
close
file
16
$a0 = file descriptor

* *
Examples of Simple I/O for lab today
* *
#*H%2.&(".(2.& +@+% ((
( C2(PESQ)* #*load*service*number*in to*$v0( ( (((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((
( C2(P"SQR ( #* load*value*to*be*printed*i nto*$a0( ( ( ((((((((((((((((((((((((
( ,',1"CC* * (
*
#H%2.&("(.0CC<&+%B2."& +/(,&%2. @**
* C2(PESQ?(* #load*s ervice*number*in*$v0( ( ( ( ( (
( C"(P"SQH%$BH&[ ,&%2.@( ((
* * * #*load*a ddress*of*string*to*be*printe d*into*$a0*
* ,',1"CC((
(
* #*the*null‐termi nated*string* must*be* defined*in*data*segment*
* T/"&"(
(((((H%$BH&[,&%2 .@\((T",122W(UO.&+% ( "(E"C0+\( U* ( ( (
( (
#(%+"/(2.(".(2.&+@+%**
* C2(PESQR( #load*s ervice*number*in*$v0( ( ( ( ( (
( ,',1"CC* #the*value*entered*by*the*user*is*returned*in*$v0( (
( (
( B$E+(P&SQPES* #store*value*entered*into* another*register* *

*
#*%+"/(2.("(,&%2.@* *
* C2(PESQ]((( * ***#load*service*number*in * $v0*
C"(P"SQ".,=+%* ***#pu t*address* of*answe r*string*in* $a0* *
* C=(P")Q"C+.@&9* ***#put*length*of * string*in*$ a1* * * * *
,',1"CC* **#*string*is*stored*in*memory*at*the*answer%*lo cation*
*
#answe r*and*ale ngth*mu st*be*defined*in*da ta*segme nt*
*********T/"&" (
".,=+%\((T,H"1+ ( RS**#*allocate*sp ace*for*str i ng*to*be* stored*
* "C+.@&9\ ( ( T =$%/(RS***#length*of*string*to*be* entered(
*
#(&+%B2."&+(+K+10& 2$.($G(H%$@%"B *
C2(PESQ)S( #load*s ervice*number*in*$v0( ( ( (
( ,',1"CC* #should*alway s*be*the* f i nal*instructions*i n*your*pr ogram*
* (