EMBEDDED ARM(acorn RISC machine):
It is so called ARM as it is discovered by the British company ARM holdings.
This architecture can be specifically useful for supercomputers as it is very efficient in multitasking.
This is particularly reduced set instruction computer. It is used a lot and prominent in 32-bit architectures.
Some prominent types of ARM processors:
The company constantly releases an update in order to tweak any possible bugs(errors) in the manufactured systems.
Reduced Instruction set computers employ a very few transistors compared to Complex instruction set computer.
By the year of 2017 ARM processors was globally dominating the market on a very large scale selling over 101 billion units.
The ACORN computer had realized how to step up the game from simple MOS technology to the ones used by IBM. Several patents were licensed by ACORN from Hitachi.
Officially THE ACORN company release ARM in the year of 1982. The primary goal of this upgrade was to obtain low latency handling like the 6502 processor.
The primary ARM application was acting as a secondary processor.
ARMv6(Advanced Reduced instruction set computer):
There had been a collaboration between Apple and VLSI technology to make an even more advanced ARM core structure known as ARMv6 which was released in 1992.
While operating at a 233MHZ frequency the machine drew only 1 watt of power.
ARMv6 comprised of 35,000 transistors as opposed to the transistor count of 30,0000 in ARMv2.
PROCESS OF DEBUGGING:
Most of the ARM processors in the 21st century allows to perform operations such as:-
1.) Break pointing of code
These provisions were made possible by the aid of oin test action group (JTAG) support.
Within ARMv7TDMI “D” denoted the debug provision whereas “I” denoted the IDE module(embedded).
INSTRUCTION ENHANCEMENT WITH DSP:
For the purpose of enhancing digital signal processing multimedia applications, a new set of instructions.
This was denoted by the addition of letter “E” to the architecture model. E.g. ARMv5TEJ.
They included updated instruction sets based on unique arithmetic operations.
There are basically 16 coprocessors available within an ARM.
Only the hardware is integrated by the chip designers using coprocessors.
Single Instruction Multiple Data(SIMD):
This came into prominence just before the advanced SIMD instruction(NEON) used nowadays.
The later versions of the ARM including the ARMv7 architecture comprised of a 3- stage pipelining process.
The current ARMv8 core architectures involve a 13 stage complex pipelining process in order to enable a quick adder and better decision predictor logic.
E.g. ARMv7TDMI and ARMv7DI were examples of the enhanced multiplier and therefore the “M” in HDMI suggests Multiplier.
It is a union of 64 and 128-bit SDMI instruction set that facilitate standard media acceleration and applications involving signal processing.
It can execute MP3 audio decoding process.
It performs SDMI processes as well as intensive gaming and graphical tasks on the processor.
It has the ability to support:-
1.) 8-bit integer
2.) 16- bit integer
3.) 32-bit integer
4.) 64-bit integer
5.) 32-bit floating point data
They Have exactly the same hardware registers such as Virtual floating pointers(VFP).
Most common ARM ARCHITECTURES:
The most commonly used architecture ARMv7A comprises of:-
Used by 32- bit cores in cortex and other non-arm cores.
Used by 32-bit cores in the Cortex- R series collection.
Used by most 32 – bit cores in the Cortex – m series collection.
ARMv8A (32/64 bit architecture):-
In this architecture(Aarch) the fundamental change includes the addition of 64 – bit architecture.
Apple company was the first to be employed in the android phone i-phone 5s.
The main advantage of this architecture was that 32-bit processes could function normally on a 64-bit Operating system.
THUMB INSTRUCTION SET:
In order to enhance the density of code compilation, some processors such as the ARMv7TDMI had employed the thumb instruction set.
Salient features of Thumb instruction set:
1.)The ARM instruction coding is done using 16- bit decoding system.
2.)Makes system optimization much easier.
3.)The data path in Gameboy is accessed through 16 – bit secondary data path which makes it convenient to put together the thumb code for the system.
SECURITY FOR ARM architecture:
Few of the ARM architectures such as ARMv6kzKZ emplots Trustzone technology which is like a secondary option to the security available on SOC.
Implementation of trust zone:- E.g. Open Virtualization
APPLICATIONS OF ARM:
They found applications in the following devices:-
1.)Personal Digital Assistants
3.) Nintendo game console
4.) Portable media player(IPAD)
6.) Car navigation systems
MOBILE OPERATING SYSTEMS WITH ARM:
- Windows phone
32 bit operating systems with ARM:
64 bit operating systems with ARM:
- Windows 10 (currently supports 32 bit (x86), 32 bit ARM, will support 64- bit ARM in future)