Handout 14

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<ul><li> 1. Handout 14 Computer Buses</li></ul> <p> 2. Buses </p> <ul><li>A bus is a subsystem that transfers data between computer components inside a computer or between computers. </li></ul> <ul><li>A bus can logically connect several peripherals over the same set of wires.</li></ul> <ul><li>Each bus defines its set of connectors to physically plug devices, cards or cables together. </li></ul> <p> 3. Buses </p> <ul><li>Early computer buses were literally parallel electrical buses with multiple connections. </li></ul> <ul><li>The term is now used for any physical arrangement that provides the same logical functionality as a parallel electrical bus. </li></ul> <ul><li>Modern computer buses can use both parallel and bit-serial connections. </li></ul> <p> 4. Characteristics of a Bus </p> <ul><li>A bus is characterized by the amount of information that can be transmitted at once. </li></ul> <ul><li>This amount, expressed in bits, corresponds to the number of physical lines over which data is sent simultaneously.</li></ul> <ul><li>The term "width" is used to refer to the number of bits that a bus can transmit at once.</li></ul> <p> 5. Characteristics of a Bus </p> <ul><li>The bus speed is also defined by its frequency (expressed in Hertz), the number of data packets sent or received per second. </li></ul> <ul><li>Each time that data is sent or received is called a cycle.</li></ul> <ul><li>The maximum transfer speed of the bus, is the amount of data which it can transport per unit of time, </li></ul> <p> 6. Bus Subassembly </p> <ul><li>Theaddress bus(sometimes called the memory bus) transports memory addresses which the processor wants to access in order to read or write data. It is a unidirectional bus.</li></ul> <ul><li>Thedata bustransfers instructions coming from or going to the processor. It is a bi-directional bus.</li></ul> <ul><li>Thecontrol bus(or command bus) transports orders and synchronization signals coming from the control unit and traveling to all other hardware components. It is a bi-directional bus, as it also transmits response signals from the hardware.</li></ul> <p> 7. IC (Inter-Integrated Circuit)</p> <ul><li>Is a multi-masterserialcomputer bus invented by Philips that is used to attach low-speed peripherals to a motherboard, embedded system, or cellphone. </li></ul> <ul><li>The IC reference design has a 7-bit address space with 16 reserved addresses (maximum of 112 nodes) </li></ul> <p> 8. IC </p> <ul><li>The most common IC bus modes are the 100 kbit/s standard mode and the 10 kbit/s low-speed mode. </li></ul> <p> 9. IC Configuration </p> <ul><li>Clock (SCL) </li></ul> <ul><li>Data (SDA) lines</li></ul> <ul><li>Master node node that issues the clock and addresses slaves</li></ul> <ul><li>Slave node node that receives the clock line and address.</li></ul> <p> 10. IC to Your PC </p> <ul><li>USB-I2C USB to I2C Communications Module. </li></ul> <ul><li>http://www.robot-electronics.co.uk/htm/usb_i2c_tech.htm </li></ul> <ul><li>A Source:http://www.trossenrobotics.com/devantech-usb-to-12c-adapter.aspx?feed=Froogle </li></ul> <ul><li>18-Bit Analog-to-Digital Converter with I2C Interface and On-Board Reference </li></ul> <p> 11. Computer Bus Subassembly 12. Bus Configuration 13. Bus Configuration </p> <ul><li>Backside bus (BSB), is used to connect the CPU to CPU cache memory. </li></ul> <ul><li>Frontside bus (FSB), system bus or local bus, connects the microprocessor and the system memory. </li></ul> <ul><li>Bus bridges interconnect different bus protocols. </li></ul> <ul><li>AGP is a high-speed point-to-point channel for attaching a graphics card to a computer's motherboard. </li></ul> <p> 14. ISA Bus </p> <ul><li>Industry Standard Architecture. </li></ul> <ul><li>The ISA bus was developed by a team at IBM as part of the IBM PC project in 1981. </li></ul> <ul><li>It originated as an 8-bit system.</li></ul> <p> 15. ISA Sockets 16. ISA Card 17. Historical background for the I/O buses 18. ISA Bus 19. PCI Bus </p> <ul><li>PCI Local Bus (Peripheral Component Interconnect) </li></ul> <ul><li>Typical PCI cards used in PCs include: network cards, sound cards, modems, extra ports such as USB or serial, TV tuner cards and disk controllers. </li></ul> <ul><li>Work on PCI began at Intel's Architecture Lab circa 1990. </li></ul> <p> 20. PCI Slots 21. PCI Card 22. Conventional hardware specifications </p> <ul><li>These specifications represent the most common version of PCI used in normal PCs. </li></ul> <ul><li><ul><li><ul><li>33.33 MHz clock with synchronous transfers</li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>Peak transfer rate of 133 MB/s for 32-bit bus width (33.33 MHz 32 bits 8 bits/byte = 133 MB/s)</li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>Peak transfer rate of 266 MB/s for 64-bit bus width</li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>32-bit or 64-bit bus width</li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>32-bit address space (4 gigabytes)</li></ul></li></ul></li></ul> <p> 23. PCI Keying 24. USB </p> <ul><li>Universal Serial Bus. </li></ul> <ul><li>A serial bus standard to interface devices to a host computer.</li></ul> <ul><li>USB was designed to allow many peripherals to be connected using a single standardized interface socket and to improve plug 'n' play capabilities by allowing hot swapping. </li></ul> <p> 25. History </p> <ul><li>The USB 1.0 specification model was introduced in 1996. </li></ul> <ul><li>USB was created by the core group of companies that consisted of Intel, Compaq, Microsoft, Digital, IBM, and Northern Telecom. </li></ul> <p> 26. USB Speeds </p> <ul><li>TheFull Speedrate of 12 Mbit/s (1.5 MB/s) is the basic USB data rate defined by USB 1.1.</li></ul> <ul><li>ALow Speedrate of 1.5 Mbit/s (187.5 kB/s) is defined by USB 1.0. It is very similar to full speed operation except that each bit takes 8 times as long to transmit. It is intended primarily to save cost in low-bandwidth Human Interface Devices (HID) such as keyboards, mice, and joysticks.</li></ul> <ul><li>AHigh-Speed(USB 2.0) rate of 480 Mbit/s (60 MB/s) was introduced in 2001. All high-speed devices are capable of falling back to full-speed operation if necessary.</li></ul> <p> 27. USB Connectors 28. A Non-Standard USB Device 29. USB </p> <ul><li>The maximum length of a standard USB cable is 5.0 meters (16.4 ft).</li></ul> <ul><li>The primary reason for this limit is the maximum allowed round-trip delay of about 1500 ns.</li></ul> <ul><li>If a USB device does not answer to host commands within the allowed time, the host considers the command to be lost.</li></ul> <p> 30. Device Bandwidths </p> <ul><li>Just more than you care to know. </li></ul> <ul><li>http:// en.wikipedia.org/wiki/List_of_device_bandwidths </li></ul> <p> 31. References </p> <ul><li>http://computer.howstuffworks.com/pci.htm </li></ul> <ul><li>http://members.tripod.com/~newwave_2/page1.htm </li></ul> <ul><li>http://en.wikipedia.org/wiki/Bus_(computing) </li></ul> <ul><li>http://www.karbosguide.com/hardware/module2c1.htm </li></ul>