CP 1610 Introduction to Computer Components The Motherboard

CP 1610: Introduction to Computer Components The Motherboard

What is the Motherboard? The largest circuit board in a computer. n The means by which all devices are connected to each other, and the CPU. n Also called the system board. n

Parts on a Motherboard

What is the CPU Central Processing Unit. n Also called the processor or the microprocessor. n The most important chip in the computer. n The brain, or command centre. n

Parts of the CPU n Input/output (I/O) unit n Arithmetic logic unit(s) (ALU) n Control unit

How the CPU Works

Parking 10 9 ALU (Registers) You need to go to Building 10! Parking (Internal Cache) The I/O Unit is like the security guard at the front gate. The Control Unit (CU) is like a Please wait until the road is clear, and I will open security guard the gate! directing students to the correct building.

CISC vs. RISC Processors n CISC ¨ Complex n Instruction Set Code RISC ¨ Reduced Instruction Set Code

CISC RISC

Other Parts on the Motherboard n n n n System Bus CMOS BIOS The Chipset System Clock Expansion Slots Floppy and Disk Drive Connections Memory

System Bus Metal lines (traces) connecting parts on the motherboard. n Allow data to travel between devices and the CPU. n Like a system of roads throughout a city. n Can be expanded to other parts (like highways connecting towns and cities). n

CMOS n Chip that saves your system settings: ¨ Date and time ¨ Hardware configuration ¨ Boot device order Has a battery so that it can save your settings even when the computer is off n CMOS stands for Complex Metal Oxide Semiconductor n

BIOS n n Basic Input/Output System Stores basic instructions on how the computer can talk to: ¨ Keyboard ¨ Mouse ¨ Monitor ¨ Memory n n Allows a computer to operate basic functions without any other software installed Is the same for ALL computers.

The Chipset The chipset controls most parts of the computer. n It handles ‘routine’ work, so the CPU can handle more important processing. n Some of the chips in the chipset include: n ¨ Interrupt Controller ¨ Keyboard Controller ¨ DMA Controller

The Interrupt Controller n What is an Interrupt? ¨ Lots of devices want to get the CPU’s attention; ¨ An interrupt is a signal that tells the CPU which device is calling, or sending data; ¨ The Interrupt Controller is a chip that controls the flow of data on the system bus, and lets the CPU know which device needs it;

Who is trying to call me? This better be important! The CPU (Everyone wants his attention!) Don’t worry… I can direct traffic for you! The Interrupt Controller is like a police offer directing traffic at a busy roundabout. Some devices get priority over others

How the Interrupt Controller Works 0 1 2 3 4 5 Floppy 6 7 9 10 11 PS/2 Mouse 12 13 14 15 Interrupt Controller 8 Interrupt Controller System Clock Keyboard CPU

Common Interrupt Requests (IRQ’s) IRQ USUAL FUNCTION/DEVICE 0 System Timer 1 Keyboard 2 2 nd IRQ controller 3 COM 2: 4 COM 1: 5 Free (used by LPT 2: or sound card) 6 Floppy disk 7 LPT 1: 8 Real Time Clock (RTC) 9 Free (may be labeled/appear as IRQ 2) 10 Free (often used by sound cards) 11 Free 12 PS/2 mouse 13 Math coprocessor on CPU (used) 14 Primary IDE 15 Secondary IDE

Keyboard Controller n The Keyboard Controller provides the following functions: ¨ Keyboard Control and Interpretation. ¨ PS/2 Mouse Support. ¨ Access to the High Memory Area. n The Keyboard Controller is often not needed in newer computers.

The DMA Controller Direct Memory Access n Sometimes devices may want to ‘talk’ to each other without ‘going through’ the CPU. n DMA Controller controls access to the system bus, and RAM, and bypasses the CPU. n

I’m busy with official business… don’t bother me! The CPU (Not everyone needs his attention!) This better be important Thanks, guess I if youofficer. want to. I keep don’t need to bother with going down Madinat Don’t worry, Sarge! I’ll direct this car! Khalifa! this car through the roundabout! The Interrupt Controller The DMA Controller is like a second traffic officer who handles traffic not going to the CPU Can I go now? I’m only going to Beep!Mc. Donald’s! Do I really Beep!need to go see the CPU first? Some devices don’t need to talk to the CPU

The System Clock Crystal that emits a pulse/signal. n Acts like a drummer in a rock band. n Pulses provide timing for the CPU and other devices. n

Clock Speeds n Measured in Hertz ¨ Cycles n per second Speed of the Motherboard: ¨ Megahertz n (MHz) Speed of the CPU: ¨ Gigahertz (GHz)

Expansion Slots Allow you to ‘expand’ the capabilities of your computer. n Connect new circuit boards to your motherboard. n Connect the data buses (roads) on the expansion cards to the system bus (roads) on the motherboard. n

Common Expansion Cards Sound Cards n Modems n Network Cards n Video Cards n Specialty Cards n

Types of Expansion Slots n ISA ¨ Industry Standard Architecture ¨ Older, ‘legacy’ cards n PCI ¨ Peripheral Component Interconnect ¨ Newer, faster expansion cards n AGP ¨ Accelerated Graphics Port

Floppy and Disk Drive Connections Special slots for ‘ribbon’ (data) cables. n Allow you to connect: n ¨ Floppy disk drives; ¨ Hard disk drives; ¨ CD/DVD drives; ¨ Zip disk drives; ¨ Etc…

Floppy Drives n n There is usually one floppy disk drive connection. A floppy controller chip on the motherboard controls talking to, and fuctions of the floppy drive.

EIDE Connections n Used to connect: ¨ Hard disk drives; ¨ CD/DVD drives; n Two connectors on the motherboard. ¨ Each connector can connect two devices; ¨ Up to four EIDI devices can be connected;

Memory Devices Hold data and instructions. n Types of Memory: n ¨ System ¨ RAM; ¨ ROM; Memory;

System Memory n n n 1 Megabyte (1 MB) Built into motherboard. Maximum memory that could be handled by: ¨ Older PC’s; ¨ New PC’s before system drivers and OS are booted; n Hold data and instructions for: ¨ System drivers; ¨ Programs used by the user;

Anything above 1 MB Reserved for device drivers and system functions Available to the user for any software

RAM vs. ROM n RAM ¨ Random n Access Memory ¨ Stores data and instructions ¨ Volatile n Examples: ¨ RAM chips ¨ CMOS ROM ¨ Read Only Memory ¨ Stores basic system settings ¨ Non-volatile n Example: ¨ BIOS

Types of Motherboards n Choice of motherboard affects: ¨ Capabilities and limitations of system; ¨ Type of computer case needed; n Common types of motherboards: ¨ ATX ¨ Backplane

The AT Motherboard n n Smaller Used for classic Pentium CPU Uses SIMM RAM Uses P 8 and P 9 power connectors

The ATX Motherboard n n n Faster Easier to install More power management features Uses DIMM RAM Has a PI power connector

Backplane Motherboards Actually built into the computer case. n More difficult to make upgrades. n Not as popular. n