Transcript Appendix A: MIPS R2000 Assembly Language

Appendix A:
MIPS Assembly
Language
Instruction Format
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R-type
I-type
J-type
SPIM and MIPS Architecture
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A MIPS processor consists of an integer
processing unit (the CPU) and a collection of
coprocessors.
SPIM simulates two coprocessors:
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coprocessor 0 handles exceptions, interrupts and
the virtual memory system
coprocessor 1 is the floating-point unit
Addressing Modes
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MIPS is a load-store architecture
Only load and store instructions access
memory
Computation instructions operates only on
values in registers.
The bare machine provides only one
addressing mode: c(rx), c+rx
Virtual machine provides other modes.
Data Alignment
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Most load and store instructions operate only on
aligned data.
A quantity is aligned if its memory address is a
multiple of its size in bytes.
Example: a half-word object must be stored at a
even address.
MIPS provides some instructions to manipulate
unaligned data. (lwl, lwr, swl, swr)
Exceptions and Interrupts
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Will be discussed in Chapter 5.
Deal with exceptions caused by errors during
an instruction’s execution; or external
interrupts caused by I/O devices.
SPIM only simulates part of MIPS’ exception
facility.
BadVAddr, Status, Cause, EPC
Instruction Categories
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Arithmetic and Logical Instructions
Constant-Manipulating Instructions
Comparison Instructions
Branch Instructions
Jump Instructions
Load Instructions
Store Instructions
Data Movement Instructions
Floating-Point Instructions
Exception and Interrupt Instructions
Assembler Syntax
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.align n : align the next datum on a 2^n
byte boundary.
.ascii str , asciiz str
.byte b1,…,bn
.data <addr>
.double d1,..,dn
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More on Pages A-47 and A-48
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System Calls
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System services (Figure A.9.1):
print_int, print_float, print_double,
print_string, read_int, read_float,
read_double, read_string, srbk, exit
Figure A.9.1
Example
.data
str:
.asciiz “the answer= “
.text
li
$v0,4 # print_str
la
$a0,str # addr of string
syscall
to print
Programming Assignment
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A.6 (due on 10/5/2005)
A.7 (due on 10/5/2005)
A.8 (due on 10/12/2005)
Submit a hardcopy including the source code
and the results of executing the program.
Also send an electronic copy of the source
code to your TA (g9304).