Capability of processor determine the capability of the computer system. Therefore, processor is the key element or heart of a computer system. Other than PC, microprocessors are used in various computerized system such as industrial automation.

Number of bits capacities Number of bits μP can handle at any one time determined the capacities of μP. 2 n Improvement number of bits determined by 2 n. Manufacturer/ Year INTELMOTOROLA , 4 bit, 108 kHz, contains 2300 transistors 6800, 8 bit , 8 bit, 2 MHz, contains transistors 68000, 16 bit , 16 bit, 8-12 MHz, contains transistors 68020, 32 bit , 32 bit, MHz, contains transistors 68030, 32 bit , 32 bit, MHz, contains 1.2 million transistors 68040, 32 bit 1993Pentium, 64 bit, MHz, contains 3.1 million transistors 68060, 64 bit 1997Pentium II, 300 MHz ::::

M FAMILY Comparative of various M family µP. All chips have 32 bit CPU register, but the early µP are 16 bit systems. Why Motorola built (8 bit) after (16 bit)?

Capacity of µP: Bits of data – size of data bus memory size accessible – size of address bus Data size – data stored in a single cell of memory. (size of data bus determine the data size) 1 bit : the smallest. nibble 4 bit : nibble. byte 8 bit : byte. word 16 bit : word. long 32 bit : long word. Data size n Data typeData capacity 2 n Range 1Bit20 – 1 4Nibble Byte2560 – Word – Long Word4,294,967, ,294,967,295

Tocci, 1991 sequence of operations A digital comp is a combination of digital devices and circuits that can perform a programmed sequence of operations (program) with a minimum of human intervention. Program is a set of coded instructions, stored in the comp’s internal memory executed by the computer in order. all under control of the program Comp do not think but high speed machine that can manipulate data, solve problems and make decision, all under control of the program.

Basic computer system

Basic Microcomputer system

Microcomputer system with Intel 8085 microprocessor

Microcomputer system with Motorola microprocessor

transfer A wire used to transfer a signal from one point to another.

data size Data bus – bidirectional (read or write). Determine the data size. Transfer data in parallel.

number of memory cells (lines) Address bus – unidirectional. Transfer data in parallel. Determine the number of memory cells (lines). synchronize the activities Control bus – bidirectional (not the same line). set of signals used to synchronize the activities of the separate microcomputer element. Ex : Read, Write Ex : RESET, INTR

How computer system works? ROM permanently stores a short program (initial). read When comp is ON, CPU read program in ROM 1. reset connected devices to standby mode. 2. transfer system programs (OS) from permanent storage (hard disk) to RAM. 3. System program will provide needs for user.

Fetch & execute cycle

Fetch cycle – a, b, c Execute cycle – e

Example 2-1 (page 28)

Read in fetch cycle

Write in execute cycle

Microprocessor packaged in IC chip. The pins configuration / block diagram used to explain or analyze the architecture of a microprocessor. Figure 2.12 – Intel 8085 microprocessor chip Motorola microprocessor Figure 2.13 – Motorola microprocessor chip

Internal structure µP consist of : 1. control & timing – fetch cycle, decode, execute cycle. supply clock / timing. 2. register – temporary. faster than memory. Various types. 3. ALU – arithmetic & logic operation.

Therefore, µP performs a number of functions, includes: Providing timing and control signal. Fetching instruction and data. Decoding instruction. Transferring data between I/O and memory. Performing A&L operation. Responding to I/O-generated control signal such as RESET or INTERRUPT.

Register set (32 bit) 8 data register 7 address register 2 stack pointer 1 program counter 1 status register

Intel 8085 clock system and bus cycle timing

Motorola clock system and bus cycle timing Bus cycle (machine cycle) InstructionNo. of Read cycle No. of Write cycle MOVE.LD2,D310 MOVE.W34(A1),D230 MOVE.BD3,60(A2)21 ADD.L56(A3),D440 ADD.LD4,56(A3)42 ADDI.W#$1234,56(A3)41 JMPXXXX.W20 JSRXXXX.W22 TRAP#543