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Conversion of unsigned numbers between number bases: In the following
table, all numbers in the same column have the same base, while all
numbers in each row have the same value, fill in the blanks.
(0.2 points per blank.)
Base 2 Base 8 Base 10 Base 16
11101011 353 235 DB
101010 _____ _____ _____
______ 127 _____ _____
______ _____ 127 _____
______ _____ _____ 127
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Two's complement numbers: The following table contains conventional
signed decimal numbers and their 6-bit 2's complement binary
representations. (0.4 per blank):
Decimal -25 20 -12 ______ ______
Binary 100111 ________ ________ 010110 110010
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Assembly pseudo operations: Show the result of assembling the following
M68000 code fragment into memory, assuming that the initial value of the
location counter is 00100000 (hexadecimal). Show your results as consecutive
32 bit longwords expressed in hexadecimal, showing unknown values as ?
(3 points)
Location Value
A: EQU $1
_________________ _________________
; comment
DC.L A _________________ _________________
DC.L B
DC.L C _________________ _________________
DC.B 'ABC',0
B: DS.B 3 _________________ _________________
C: DS.B A
_________________ _________________
_________________ _________________
_________________ _________________
_________________ _________________
_________________ _________________
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M68000 instruction format: Show the result of assembling the following
M68000 code fragment into memory, assuming the initial value of the location
counter is 0. Show your results as consecutive 16 bit words expressed in
binary. (2 points)
Location Value
MOVE.L (SP),$1234(A3)
ADDQ.W #7,SP ________ ___________________
CMPA.W -(A3),A0
________ ___________________
________ ___________________
________ ___________________
________ ___________________
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M68000 Programming: Write a sequence of M68000 assembly instructions
to bridge the gap between the following precondition and postcondition.
(3 points)
; Precondition: A0 points to a record in memory.
; X and Y are symbolic names for fields in the record.
; Field X is a word; field Y is an array of 20
; long words (array indices go from 0 to 19).
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
; Postcondition: D0 holds A0^.Y[X] (or A0->Y[X] in C)