EP1200 Introduction to Computing Systems Engineering. Computer Architecture

Transcription

1 EP1200 Introduction to omputing Systems Engineering omputer Architecture

2 Perspective on Machine and Assembly Languages Hack is a simple machine language Designed for the simple Hack computer architecture Few registers One data type (integer) Multiplication and division in software umbersome programming no space for a memory address within an instruction User friendly syntax: D=D+A instead of ADD D,D,A 2

3 Perspective on Machine and Assembly Languages Machine languages classification Traditionally: complex hardware or long code IS complex instruction set computer (Intel, AMD) little memory requirement, complicated PU HW RIS reduced instruction set (mobile systems, game consoles but even supercomputers) Long code, emerged when memory became cheap and fast New variants: MIS minimal instruction set (for embedded systems, special purpose processors) VLIW very long instruction word (for parallel processing) 3

4 Perspective on Machine and Assembly Languages Some typical differences operations per instruction IS allows load and store RIS only one memory operation per instruction load or store Operands per instruction ½ address machine: Hack 1 address machine: one operand. 3 address machines E.g. add a,b,c (c=a+b, in one instruction) 4

5 Where we are at: Human Thought Abstract design hapters 9, 12 abstract interface H.L. Language & Operating Sys. ompiler hapters abstract interface Virtual Machine Software hierarchy VM Translator hapters 7-8 abstract interface Assembly Language Assembler hapter 6 abstract interface Machine Language omputer Architecture hapters 4-5 Hardware hierarchy abstract interface Hardware Platform Gate Logic hapters 1-3 abstract interface hips & Logic Gates Electrical Engineering Physics 5

6 omputer architecture Von Neumann machine (circa 1940) PU Arithmetic Logic Unit (ALU) Input device (data + instructions) Registers ontrol Output device Stored program concept: the program code is stored in memory and can be manipulated, just like data John Von Neumann (and others) made it possible Andy Grove (Intel) (and others) made it small and fast 6

7 The Hack chip-set and hardware platform Elementary logic gates ombinational chips Sequential chips omputer Architecture Nand HalfAdder DFF Not done FullAdder Bit PU And Add Register omputer Or Xor Inc ALU RAM8 RAM64 this lecture Mux RAM512 Dmux Not done RAM4K RAMK And P Or Mux done Etc. 7

8 The Hack computer A -bit Von Neumann platform (actually more Harvard platform: instruction and data memory separated) Designed to execute programs written in the Hack machine language the architecture and the language needs to be designed together! inm writem Instruction (ROM32K) instruction PU outm addressm pc Data () reset 8

9 The Hack computer inm writem Instruction (ROM32K) instruction PU outm addressm pc Data () Main parts of the Hack computer reset Instruction memory (ROM) we consider it given Data memory: (RAM), Screen (memory map), Keyboard (memory map) entral Processing Unit, PU omputer (the logic that holds everything together) 9

10 The Hack computer implementation inm writem Instruction (ROM32K) instruction PU outm addressm pc Data () reset ROM, RAM, Wiring as on the block diagram implementation is simple 10

11 Instruction memory - ROM address ROM32K out 15 Function: The ROM is pre-loaded with a program written in the Hack machine language (note, you can not dynamically change the program!) The ROM chip always emits a -bit number, this number is interpreted as the current instruction. We consider the ROM given, you do not need to implement it. 11

12 (RAM, Screen, Keyboard) conceptual / programmer s view Data Screen map Keyboard map Screen Using the memory: Keyboard To record or recall values (e.g. variables, objects, arrays), use the first K words of the memory To write to the screen (or read the screen), use the next 8K words of the memory To read which key is currently pressed, use the next word of the memory. 12

13 : physical implementation load load in 0 RAMK (K mem. chip) out in address RAMK out address Screen (8K mem. chip) Keyboard (one register) Screen Keyboard Keyboard 15 in address 15 load Screen Keyboard out out Physical Screen The chip: integrates the three chip-parts RAMK, Screen, and Keyboard into a single address space. Implementation challenge: addressing 13

14 PU ALU, A, D registers, P A Hack machine language instruction stated as a - bit value from data memory from instruction memory inm instruction reset outm 1 PU writem addressm pc to data memory to instruction memory PU elements ALU (arithmetic unit) A (address), D (data) registers and P (program counter) PU operation Executes HAK machine language instruction Reads from and writes to memory Reads or sets A, D and P registers (inside the PU) 14

15 PU (ALU, registers A, D, P) implementation ALU output D D decode outm instruction Mux A A Mux A/M ALU inm M writem A addressm reset A P pc 15

16 PU (ALU, registers A, D, P) implementation Implementation is challenging ALU functions Machine Language instructions ALU output Break it to small problems decode D D outm Instruction decoding instruction Mux A A Mux A/M ALU D register wiring inm M A writem addressm reset A register wiring A P pc ALU: inputs and outputs Jumps and Program counter

17 Project - omputer-on-a-chip reset omputer Screen Keyboard 17

18 Project - omputer-on-a-chip implementation (hapter 5 project) inm writem ROM given Implement (RAM, Screen, Keyboard) in the hardware simulator Instruction (ROM32K) instruction PU outm addressm pc Data () Implement PU, (A-register, D-register assumed to be available), we provide commented reset template Implement omputer from PU, ROM and Test and PU in separation, then test the omputer (test programs are available) Always comment your code! 18

19 Project - omputer-on-a-chip implementation Reading and tools Repeat hapter 2 ALU Repeat hapter 4 Machine Language basic concepts hapter 5 omputer architecture Tools: Hardware simulator (the one used in Projects 1-2) Hand in project by April 4,