2.3 Overview of the arm embedded processors from texas instruments

ARM embedded processors – selecting the right one

ARM embedded processors are ubiquitous. With the vast number of ARM-based processors available, selecting the right one for a senior project can seem daunting. This chapter will help you select the right TI ARM processor.

At a high level, ARM embedded processors can be split into three tiers of performance: the Cortex-A, -R and –M series.

ARM Cortex-A microprocessors

• Highest-performance microprocessors/use external memory.
• For use with a complex operating system.
• Applications:
  • Computing, enterprise, handset, digital home, industrial, wireless infrastructure [ http://www.arm.com/products/processors/cortex-a/index.php ].
  .
• Author's note:
  • Use a Cortex-A device if you:
    • Are ready and willing to develop high-complexity software for your application, including running, debugging and compiling high-level operating systems like Windows, Linux or Android.
    • Are using the microprocessor to program a user interface larger than 7 inches, or wish to display any kind of streaming video on any size display.
    • You wish to program a field bus protocol.
  • If you are interested in working with a Cortex-A device from TI, see the BeagleBone website at http://beagleboard.org/bone/ .

ARM Cortex-R microcontrollers

• Medium-performance real-time microcontrollers/use integrated memory.
• Designed for safety- and life-critical applications with precise real-time requirements.
• Applications:
  • Storage, enterprise, digital home, cameras, medical, industrial, automotive [ http://www.arm.com/products/processors/cortex-r/index.php ].
• Author's note:
  • Use a Cortex-R device if you:
    • Are ready and willing to develop medium-complexity software, especially if you are interested in safety-critical embedded software development.
    • Want to develop a real transportation or safety application.
  • If you are interested in working with a Cortex-R device from TI, see the TMS570 microcontroller USB kit website at http://www.ti.com/tool/tmdx570ls20susb .

ARM Cortex-M microcontrollers

• Lowest-power microcontrollers/use integrated memory.
• Designed for cost- and power-sensitive applications.
• Applications:
  • Smart metering, human interface, industrial, white goods, consumer, portable medical [ http://www.arm.com/products/processors/cortex-a/index.php ].
  .
• Author's note:
  • Use a Cortex-M device if you:
    • Are interested in the lowest-complexity solution for your application.
    • Can meet the needs of your application with 150 MHz or less and without a multithreaded OS running in the system.
    • Are looking for the smallest, least-expensive or lowest-power ARM device.
  • If you are interested in working with a Cortex-M device from TI, visit the Stellaris® LaunchPad™ development tool website at http://www.ti.com/stellaris-launchpad .

TI's ARM-based platforms (as of August 2012) are outlined in Figure 1.

Stellaris microcontrollers. Offering performance up to 80 MHz and a high degree of connectivity and analog integration to the microcontroller markets, Stellaris MCUs are ideal for applications that require memory, analog components and communications interfaces to be on a single chip within a compact package.