 Introduction to Micro processor Introduction to Micro processor  Microprocessor instruction and opcodes Microprocessor instruction and opcodes  Mnemonics Mnemonics

OBJECTIVES  Understand what a microprocessor is, what it does, and how it works.  Understand the concepts of RAM and ROM computer memory and how memory is accessed via the address and data buses.  Understand how parallel and serial data interfaces work.  Perform relevant calculations pertaining to analog-to- digital converters and digital-to-analog converters.  Understand the principles of digital controller software.  Recognize and describe the characteristics of the various types of available digital controllers, that is, microcontrollers, single-board computers, programmable logic controllers, and personal computers.

 Microprocessors ushered in a whole new era for control systems electronics.  Microprocessors require additional components to be useful – RAM, ROM, etc. BACK

 A computer is made up of four basic blocks: ◦ Central Processing Unit (CPU)  Does the actual computing.  Arithmetic Unit – performs math and logic  Control: Manages flow of data ◦ Memory – Data is contained in memory locations at specified addresses.  RAM – volatile, read/write memory  ROM – nonvolatile, read only  EPROM/EEPROM/Flash – Erasable ROM

 Input/Output ports: Used for connections to devices.  Busing: ◦ Devices are multiplexed using 3 major buses:  Address Bus – To specify the device or memory location to communicate with.  Data Bus – To transfer data between the CPU and device.  Control Bus – Timing and event control, such as read and write operations.

 Each processor has its own instruction set of commands to control its operation. ◦ Move data ◦ Perform math operations ◦ Perform logical operations  Each instruction has a unique Op-code, a binary value associated to it or 4Dh.  An Accumulator is staging area for data – data is moved into it, and operations are performed on that data. BACK

 Machine Code ◦ The program the CPU follows represented in binary or hex.  Mnemonics ◦ Abbreviations representing an op-code. Programs written in assembly language use mnemonics.  Program counter ◦ Used to point to the memory address of the instruction to be performed.  Fetch-execute cycles ◦ Performed to bring an instruction into memory and execute it. BACK