Lesson 25 Choosing the right core (Lecture 7).ppt
- 1. Lesson 25 Choosing the right core Unit 9 Embedded application
- 2. 25/1/21 2 Lesson 25 Choosing the right core • Backgrounds • Text tour • Language in use – Vocabulary
- 3. 25/1/21 3 • Terminology –cross-compiler A cross compiler is a compiler capable of creating executable code for a platform other than the one on which the compiler is running. For example, a compiler that runs on a Windows 7 PC but generates code that runs on Android Smartphone is a cross compiler. Backgrounds
- 4. 25/1/21 4 CISC: Complex Instruction Set Computer Complex instruction set computing (CISC) is a processor design, where single instructions can execute several low- level operations (such as a load from memory, an arithmetic operation and a memory store) or are capable of multi-step operations or addressing modes within single instructions. Backgrounds RISC: Reduced Instruction Set Computer A reduced instruction set computer or RISC, is one whose instruction set architecture (ISA) has a set of attributes that allows it to have a lower cycles per instruction (CPI) than a complex instruction set computer (CISC).
- 5. When executed, this instruction loads the two values into separate registers, multiplies the operands in the execution unit and then stores the product in the appropriate register.
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- 8. 25/1/21 8 Text tour • Outline – Introduction (para.1, 2) – CISC Platforms and Intel x86 Core (para.3- 5) • Advantages • Downsides • Recommendation – RISC Platforms and ARM Core(para.6-9) • Discussion on some candidates • ARM’s advantages • Summary
- 9. 25/1/21 9 • Main 32-bit cores on the market at the moment – Motorola 68000 – Intel x86 – PowerPC – MIPS – SuperH – ARM Introduction
- 10. 25/1/21 10 • You can use almost any PC-compatible operating system and free software development tools. • Installing operating systems is simple. • It is simple to interface literally thousands of peripheral components for almost any imaginable function. • Driver support exists for almost any piece of hardware • Highly integrated main boards are available. • Migrating to a slightly different hardware platform is relatively simple. CISC Platforms and Intel x86 Core Advantages
- 11. 25/1/21 11 • Very expensive • Few are true “system on chip” devices • Significant power consumption, heat and size disadvantages. • Modern x86 parts and their support chips are very high- speed devices in dense packages. • PC peripheral ICs often have very short production lifespans. CISC Platforms and Intel x86 Core Downsides
- 12. 25/1/21 12 • Code to cold-boot a “bare” PC platform is usually very complicated • JTAG-based or other hardware debugging systems aren’t usually available *JTAG (Joint Test Action Group) *Cold boot is the process of starting a computer from shutdown or a powerless state and setting it to normal working condition CISC Platforms and Intel x86 Core Downsides
- 13. 25/1/21 13 • It is recommended x86 as the platform of choice – If you are building just a few of your appliance – If you are prototyping something and want to pull together a lot of miscellaneous hardware features without spending a lot of time debugging the hardware design – It’s also a good choice for an initial production run that you can ship to early adopters while you are developing a cheaper second-round customized hardware design. CISC Platforms and Intel x86 Core Recommendation
- 14. 25/1/21 14 • MIPS, SuperH and PowerPC are good candidates for many applications – SuperH family is large and contains a wide variety of useful devices – MIPS seems to be a more widely licensed core in third- party ASICs and ASSPs – PowerPC seems to be found mainly in applications requiring very high performance – Now, the recommendation for a 32-bit embedded platform is ARM (Advanced RISC Machine) RISC Platforms and ARM Core Discussion on some candidates
- 15. 25/1/21 15 • A mature, well-understood architecture. • Small, excellent power consumption vs. performance characteristics. • Many features are tunable by the chip designer. • A huge number of attractively priced parts on the market. • Reference designs for many different peripherals. • A huge amount of freely available intellectual property. RISC Platforms and ARM Core ARM’s advantages
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- 17. 25/1/21 17 • ARM is the 32-bit 8051 (a cliché/phrase) i.e. ARM is the universal 32-bit microcontroller core known to everybody and used everywhere • ARM is to the embedded world what x86/x64 is to the desktop PC world. RISC Platforms and ARM Core Summary
- 18. 25/1/21 18 • Vocabulary – Norm refinement variant contract lifespan Language in use
- 20. 25/1/21 20 Norm in dictionary • A standard, model or pattern regarded as typical. • A mode. • An average. • The length of a vector.
- 21. 25/1/21 21 Norm in text • Compare this to the norm with embedded systems, where you will need to look at the board, work out the hardware configuration yourself, and sysgen the kernel and driver set on external hardware, probably using a cross-compiler.
- 22. 25/1/21 22 Refinement in dictionary • The act of refining. • The result of refining; an improvement or elaboration. • The state or quality of being refined; cultivation, as in manners or taste. • A keen or precise phrasing; a subtle distinction.
- 23. 25/1/21 23 Refinement in text • It is a mature, well-understood architecture with a solid engineering history and many refinements.
- 24. 25/1/21 24 Variant in dictionary • Having or exhibiting variation; differing. • Tending or liable to vary; variable. • Deviating from a standard, usually by only a slight difference. • Something that differs in form only slightly from something else, as a different spelling or pronunciation of the same word.
- 25. 25/1/21 25 Variant in text • I have found them to be fairly difficult to develop with on a shoestring budget; evaluation hardware is usually costly, and most variants of these parts are not readily available to buyers who are unable to demonstrate a need for large quantities.
- 26. 25/1/21 26 Contract in dictionary • An agreement between two or more parties, especially one that is written and enforceable by law. • The writing or document containing such an agreement. • The branch of law dealing with formal agreements between parties.
- 27. 25/1/21 27 Contract in text • Modern x86 parts and their support chips are very high- speed devices in dense packages. It is virtually impossible to hand-prototype your own design based around these parts; unless you want to spend many thousands of dollars on equipment, at the very least you will have to contract out some assembly work.
- 28. 25/1/21 28 Lifespan in dictionary • The length of time for which a person or animal lives or a thing functions: "the human life span"
- 29. 25/1/21 29 Lifespan in text • PC peripheral ICs often have very short production lifespans; twelve to eighteen months is not uncommon, so ongoing sourcing may be an issue.