3. OutLINe…..
Brief history of ARM Processor
What is processor ?
What is RISC & CISC ?
ARCHITECHTURAL simplicity
Comparison with the other processors
Advantages and Disadvantages
Applications and scopes
Conclusion
4. Chronicle of ARM
Developed at Acorn Computer Limited of
Cambridge , England between 1983 and 1985.
Initially it was known as Acorn RISC Machine
with 26 bit processor named after Berkeley
RISC project.
Later joint venture was cofounded by Acorn
and Apple designating it as ADVANCED RISC
MACHINE.
5. • What is processor ?
The processor (CPU)is the computer's brain. It allows
the processing of numeric data, meaning information
entered in binary form, and the execution of
instructions stored in memory.
What is controller ?
Controller is a chip, an expansion card, or a stand-
alone device that interfaces with a peripheral device.
This may be a link between of a computer or a
controller on an external device that manages the
operation of that device.
6. Processing modes
Serial processing
• Execution of instructions takes
place one after the other
• The biggest problem with this
is that only one bit of data can
be computed at a time, and
complex programs cannot be
split up into smaller segments.
• Time consumption takes more
compared to parallel
processing
i.e working is slow
Parallel processing
• More than one instruction execution
takes place at a time depending on the
need
• But here more than one bit of data can
be computed at a time, and complex
programs can be easily split into
segments.
• Time consumption is very less
compared to serial processing
i.e working is fast
• The simultaneous use of more than
one processor core to execute a
program or multiple computational
threads.
7. CISC: Stands for Complex Instruction
Set Computer
RISC: Stands for Reduced Instruction
Set Computer
8. Features of ARM Processors
• Auto increment and auto decrement
addressing mode
• Multiple load and store
• Conditional execution
• ALU and shifter in a single clock cycle
• Thumb instructions
• Parallel processing
• Three stage pipe line structure
9. ARM7TDMI Processor
• The ARM7TDMI processor is a member of the Advanced RISC
machine family of general purpose 32-bit microprocessor
• What does mean ARM7TDMI ?
ARM7 - 32-bit Advanced RISC Machine
T - Thumb architecture extension
• Two separate instruction sets, 32-bit ARM instructions and
16-bit Thumb instructions
D - Debug extension
M - Enhanced multiplier
I - Embedded ICE macrocell extension
11. Von Neumann architecture
• Named after
mathematician and
early computer scientist
John von Neumann.
• The von Neumann
architecture is a
computer design model
that uses a processing
unit and a single
separate storage
structure to hold both
instructions and data
12. The instruction pipeline
• It has 3- stages pipeline
• It enables several operations to take place
simultaneously
13. operat ing modes
• The ARM Processor has seven basic operating
modes
• User :Un privileged mode under which most
task run
• Fiq: Entered when a high priority interrupt is
raised
• Irq: Entered when a low priority interrupt is
raised
• System: Privileged mode using the same
registers as user mode
14. Opreating modes(contd…)
• Supervisor: Entered on reset and when
software instruction is executed
• Abort: Used to handle memory access
violations
• Undef: Used to handle undefined instructions
15. registers
• ARM has 37 registers, all of which are 32 bits
long
– 1 dedicated program counter
– 1 dedicated current program status register
– 5 dedicated saved program status registers
– 31 general purpose registers
• These registers are not all accessible at the
same time. The processor state and operating
mode determine which registers are available
to the programmer.
16.
17. ARM Instruction Set
• Every instruction contains a 4-bit condition code field in bits
31 to 28
• Data Processing Instructions
• Load Store Instructions
• Branch Instructions
18. THUMB Instruction Set
• The Thumb instruction set is mostly a subset of the32 bit
ARM instruction set, optimized for code density
• Thumb instructions are each 16 bits long, and have a
corresponding 32-bit ARM instruction that has the same
effect on the processor model.
• Thumb has all the advantages of a 32-bit core:
• 32-bit address space
• 32-bit registers
• 32-bit shifter, and Arithmetic Logic Unit (ALU)
• 32-bit memory transfer
• Thumb code is typically 65% of the size of ARM code, and
provides 160% of the performance of ARM code when
running from a 16-bit memory system.
19. differences
ARM PROCESSOR
• ARM executes almost all the
instruction in only one cycle
Ex:1 cycles for execution of
BNEQ in ARM
• RISC based architecture
• based on load store
architecture
8051 MICROCONTROLLER
• 8051 micro controller takes
more than one cycles in
almost all the instruction
except register transfer Ex:3
cycles for execution of DJNZ
in 8051
• CISC based architecture
• 8051 can access memory
directly
20. uP’s aNd dOwN’s
Merits
• Low power
consumption
• Cost sensitive
embedded application
• Cheap
• Easy to develop
• High performance
• Low code size
• Increases speed
Demerits
• Need all software’s to
be developed for new
architecture
21. scOPe aNd aPPLIcatIONs…
• Mobile phones and PDA
• Patient Monitoring
• Automotive power train
• Anti lock braking
• High end Washing Machine
• Image processing
22.
23. REFERENCES
• www.arm.com /ARM7TDMI
• Arm Limited ARM ARCHITECTURE reference
manual, Addison Wesley, June 2000
• Trevor martin the insider guide to the Philips
arm7 based micro-controller hitex (UK)Ltd,
February 2005
• www.ieee.org
24. WE EXPRESS OUR GRATITUDE TO
Dr. SHRIDHAR.K
&
ALL FACULTY
