ARM: Advance RISC Machine

ARM: Advance RISC Machine

ARM was established as a joint venture between Acorn, Apple and VLSI between Acorn, Apple and VLSI in November 1990
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ARM is the industry's leading provider of 16/32-bit embedded
RISC microprocessor solutions.
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The company licenses its high-performance, low-cost, power-efficient RISC processors  peripherals  and system chip efficient RISC processors,peripherals, and system-chipdesigns to leading international electronics companies

ARM provides comprehensive support required in developing a complete system

ARM Holdings is a technology company headquartered in Cambridge  England  UK Cambridge, England, UK.

The company is best known for its processors, although it also designs, licenses and sells software development tools under designs,licenses and sells software development tools under the Real View and KEIL brands, systems and platforms, system-on-a-chip infrastructure and software.

ARM grant license of core to different silicon vendors lik eg ATMEL, NXP, Cirrus logic etc These companies make ICs
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Examples are: LPC2148 from NXP, AT91RM9200 from ATMEL


 ARM identification:

 For Example : ARM 7 TDMI (LPC2148) 


ARM 7  modes:

1. User mode – all normal application run under this mode
2. FIQ mode – all fast interrupt data transfer or channel process service provided under this mode
3. IRQ mode – vectored(priority based) interrupt handler
4. Supervision mode – protected mode for the operating system
5. System mode – all operating related task
6. Abort mode – entered after a data or instruction Pre-fetch Abort exception
7. Undefined mode – entered when an undefined instruction is executed.