Serial Bus - material

Serial Bus:-

A) Universal serial Bus(USB):-

- It is designed to replace keyboard port, parallel port, serial port, game port etc.

by using Single connector for all.
- It can connect over 100-127 USB compatible device in daisy-chain manner.
- It is very much faster than serial ports, transmits at 12MBps rate & only 4-pin connector.
- It can transmit data in four types, divided by type of peripheral device that uses them:-

Bulk
Interrupt
Asynchronous
Control

1 Bulk:-
- Printer, Scanner and digital cameras which are send huge information to PC at one time

is bulk Transmission.

2 Interrupt:-

- Keyboard and joysticks transmit small amounts of data that must be processed immediately

uses interrupt transfer.
3 Asynchronous:-

- Telecom application must be delivered in steady and in certain order uses Asynchronous

transfer.
4 Control:-
- Hub decides which devices are plugged into it at any given time and from that it decides

how Much bandwidth is needed to which components.
- USB version 2 runs at up to 480MBps.
- USB supports all OSes.

b) Fire wire:-

- Apple created fire wire i/f to replace serial, parallel, SCSI and any other port which can

connect Components to PC.
- It is like USB supports 63 devices in a daisy chain manner.
- It is mounted on PCI card.
- It is designed to support devices that require a lot of bandwidth like Scanner, video cameras

and More
- It can support speed of 100MBps, 200MBps and 400MBps.
- It transmits data into isochronous manner means if one device is transmitting no other

device could interrupt its transmission.
- It can be any of 4-pin, 6-pin or 9-pin connector.
- Provides plug-n-play facility.

System controller:-

- Controller is a device that allows the peripheral to communicate with the rest of

the computer.

- Every peripheral device, any internal or external needs something to handle communication
between it and the computer and is achieved by system controller.