PDP-11
.
16- -. PDP-11 . DEC, , 64- VAX- Alpha.
PDP-11 216 = 65 536 (64 ) 215= 32 768 (32 ). 218 = 262 144 (256 ) 131 072 (256 ).
( ), ( ).
. 4.1.
* * * | |||||||||
* * * | |||||||||
* * * | * * * | * * * | |||||||
65 533 | 65 532 | * * * | |||||||
65 535 | 65 534 | * * * | |||||||
* * * | |||||||||
* * * | |||||||||
65 534 | |||||||||
65 535 | |||||||||
. 4.1. | |||||||||
( ). .
, , / ( ).
4 .
.
:
(),
.
(). Ζ 8 , , (R6 R7) .
R6 SP (Stack Pointer). .
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R7 PC (Program Counter). . .
.
PS (Processor Status) (. 4.2) :
( 12 15). : /. . "" .
( ). . 0 7. .
(Trap, ). T ( RTT), .
( ):
1. "",
2. V "",
3. Z " ",
4. N " ".
.
. | T | N | Z | V | C | ||||||||||
. 4.2. |
.
: . . - .
, . . .
(). :
: (1), (1 ), (3 ),
: (1), (1 ), (7 ).
, , . ( ), . , : , , , . .
.
PDP-11 . .
PDP-11 , . () (.4.3). :
,
,
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.4.3. |
. , .
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, , . ( ).
16 . . . 4.4.
, .. , . .
R | a | |||||||||||
R | b | |||||||||||
c | ||||||||||||
R | d | |||||||||||
e | ||||||||||||
f | ||||||||||||
.4.4. | ||||||||||||
. , , .. .
, . , , .
PDP-11 .
.
"a" "b" , . b . . . , ( ), .
"" , .
"d" . . , .
"" .
"f" , , . .
.
. 4. (
4. .
- | ||||
MOV | MOVB* | |||
CMP | CMPB* | , | ||
BIT | BITB* | ( **), | ||
BIC | BICB* | ( **). | ||
BIS | BISB* | ( **) | ||
ADD | SUB | 0110 1110 | ||
- | ||||
: * , ** |
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, . : (), . B. :
MOV 1 2; ,
MOV 1 2; ,
: 1 2 , .
. , , .
8 . , , . . PDP-11 . R7 . , , .
, , , , . (.5).
5
. | |||
R | |||
(R) | - | ||
(R)+ | . , | ||
@(R)+ | . , 2. | ||
(R) | , | ||
@ (R) | 2, | ||
X(R) | , | ||
@X(R) | , |
( ):
0. CLR R0; R0.
1 CLR (R0); , R0
2. ) CLR (R0)+; , R0, 2; : ;
b) mov R1, (R0)+ R1, R0 .
3. CLR &(R0)+; : .
4. ) CLR (R0) , R0, 2; : .
b) mov (R0), R1 R1, R0 .
5. CLR &(R0); : .
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6. CLR (R0) , +(R0), Ֆ .
7. CLR &(R0), , +(R0), Ֆ .
. 6.
6. | ||||
(PC)+ | #A | |||
@(PC)+ | @#A | |||
A(PC) | A | , | ||
@A(PC) | @A | , | , . |
. . , : /
(2).
c
b+0) MOV (R0)+, R1; , (, 1000) R0 R1.
b+0 . R7 ( ) b+2; (),
b+2) Ֆ .
c .
b+0) MOV (R7)+, R1; , (R7); R7 ( ) b+2. R1 , (R7), , R1 . , , (R7), , 2 b+4.
, , , . :
MOV #X, R1, #X .
(3).
, . , , :
b+0) MOV (R7)+, R1
b+2)
b+4) .
:
MOV @#X, R1, X .