Microprocessors, Lecture 1: Introduction to Microprocessors

Microprocessors, Lecture 1: Introduction to Microprocessors

Computing Systems General-purpose standalone systems (سيستم ھای نھفته ( systems Embedded 2

General-purpose standalone systems Stand-alone computer systems: used for processing and data management purposes Example: desktop PCs, laptops, tablets, servers, supercomputers, They are general-purpose: can be programmed to perform any task A computer is used for: web browsing, gaming, multimedia, database server, word processing, CAD, scientific applications, 3

General-purpose standalone systems Desktop processors Intel and AMD processors Server processors Intel, AMD, IBM, SUN, Tablet processors ARM-based System-on-Chips 4

General-Purpose Processor General-Purpose Processor Processor designed for a variety of computation tasks Each processor has an ISA and a microarchitecture ISA: Instruction Set Architecture ISA determines the set of instructions that a processor supports (and registers and addressing modes) X86 is the dominant ISA for PCs ARM is the dominant ISA for tablets and smartphones 5

A Simple (Trivial) Instruction Set Assembly instruct. First byte Second byte Operation MOV Rn, direct 0000 Rn direct Rn = M(direct) MOV direct, Rn 0001 Rn direct M(direct) = Rn MOV @Rn, Rm 0010 Rn Rm M(Rn) = Rm MOV Rn, #immed. 0011 Rn immediate Rn = immediate ADD Rn, Rm 0100 Rn Rm Rn = Rn + Rm SUB Rn, Rm 0101 Rn Rm Rn = Rn - Rm JZ Rn, relative 0110 Rn relative PC = PC+ relative (only if Rn is 0) opcode operands 6

Sample Programs C program Equivalent assembly program int total = 0; for (int i=10; i!=0; i--) total += i; // next instructions... 0 1 2 3 Loop: 5 6 7 Next: MOV R0, #0; // total = 0 MOV R1, #10; // i = 10 MOV R2, #1; // constant 1 MOV R3, #0; // constant 0 JZ R1, Next; // Done if i=0 ADD R0, R1; // total += i SUB R1, R2; // i-- JZ R3, Loop; // Jump always // next instructions... Compiler knows the machine instructions and translates the programs into machine language 7

Hardware accelerator Implementing time-consuming algorithm on hardware In processors, it is also called Co-processor Not programmable: only a fixed function CPU Co-Processor (accelerator) Arbiter Arbiter 8 Program Memory Data Memory Data Memory

Hardware accelerator The most important accelerates in processors are vector processing units (SIMD unit) SIMD= single instruction multiple data To accelerate processing on arrays 9

Processors In addition to general-purpose processors, there are other processor types ASIP ASIC GPU ASIP and ASIC are used in embedded systems 10

Application-Specific Instruction set Processor (ASIP) A processor that is programmable A general purpose processor + specific hardware resource The instruction-set is optimized for a group of applications Base instruction set + customized instructions Specific hardware resource implements the customized instructions Examples: DSPs (Digital Signal Processor) NPs (Network Processor) GPUs (Graphical Processing Unit) 11

Application Specific Instruction-set Processor Program with basic instructions set I t 1 = a * b; t 2 = b * 0xf0; ; t 3 = c * 0x12; t 4 = t 1 + t 2 ; t 5 = t 2 + t 3 ; t 6 = t 5 + t 4 ; a b c 0xf0 * * * + + + 0x12 Custom Logic *: 2 clock cycles +: 1 clock cycles Execution time: 9 clock cycles

Application Specific Instruction-set Processor (cont d) Program with extended instructions t 1 = extop1(a, b, 0xf0); t 2 = extop2(b, c, 0xf0, 0x12); t 3 = t 1 + t 2 ; a b c 0xf0 extop1 * * * + + + 0x12 extop2 Extended Instruction Set: I extop1 expop2 extops: 2 clock cycles +: 1 clock cycles Execution time: 5 clock cycles Speedup: 1.8

ASIP example- DSP A Digital signal Processor (DSP) has instructions that efficiently executes the common signal processing algorithms Typical DSP algorithms includes: Filtering, DFT, DCT Speech and image: Compression, decompression, encryption, decryption Modems: Equalization, noise and echo cancellation, better SNR Communication channel: encoding, decoding, equalization 14

ASICs Application-specific IC Digital circuit designed to execute one program Features Contains only the components needed to execute a single program No program memory Benefits Fast (optimized) Low power Small size

Design spectrum Excellent tradeoff between efficiency of ASICs and flexibility of CPUs

GPU Graphic processing unit Used for graphic processing and other parallel algorithms 17

Embedded System Embedded systems: information processing systems that are embedded into a larger product and that are normally not directly visible to user Single or limited purpose: designed to perform a single or a group of similar tasks An embedded system may perform A single task that remains fixed during the system life-time example: video-projector, printer, A group of tasks Example: a cell phone 18

Embedded systems More than 90% of computer systems are embedded! 19

Embedded systems- classification Monitoring and control functions Vehicle control, power plant control Information-processing functions Telecommunication switches, Multimedia (mp3 player), etc. A simple LCD board controller A complex telecommunication switch 20

Embedded systems Simple embedded systems are often use microcontrollers Large and complex embedded systems are composed of many devices such as FPGAs, CPUs, ASIPs, hardware accelerates, memory modules, interfaces, analog devices,. 21

Embedded systems- general picture Different application type have different requirements and characteristics 22

Embedded systems-control-based Most peripherals are organized to monitor the outside world and control it Do not require large data storage and transfer Reliability, low-cost, and low-power operation is important Microcontrollers are the best choice for this purpose A processor core with many peripheral integrated inside a single chip 23

Microcontrollers A smaller computer On-chip RAM, ROM, I/O ports... Example AVR, Intel s 8051, Zilog s Z8, and PIC 16X 24

General Purpose Microprocessors vs. Microcontrollers 25

Most common microcontrollers 8-bit microcontrollers AVR PIC HCS12 8051 32-bit microcontrollers ARM PIC32 26

Introduction Technological advances Today s chip can contains 7 billion transistors The consequences Components connected on a board can now be integrated onto single chip Hence the development of system-on-chip design 27

SoC An SoC may contain Custom hardware blocks A.K.A. Hardware accelerator DSP blocks Embedded CPU Embedded Memory Real World Interfaces (USB, PCI, Ethernet) Software (both OS and Applications) Mixed-signal Blocks DAC, ADC FPGAs 28

29 SoC evolution

30 SoC Example- a handheld device

SoC benefits Reduce size Low cost Reuse Low power High performance High reliability 31