1. Serial Interfaces

2. 2 Legacy Serial ports Parallel ports Keyboard / Mouse connectors … keyboard mouseSP PP Monitor Ethernet Sound Card Modem

3. 3 Shortcomings Interrupts I/O addresses Cabling Non-sharable interface No hot attachment Installation

4. 4 The USB Solution A unique connector Hub topology many devices to the same connector Auto detection and configuration Low power Performance

5. 5 USB - Universal Serial Bus Supports up to 127 external devices Provides power BW: –USB 1.1: 12 Mb/s –USB 2.0: 480 Mb/s

6. 6 USB Topology

7. 7 USB Configuration

8. 8 USB Devices HUB –Simplifies USB Connectivity –Detect attach and detach Functions –USB devices that transmit or receive data

9. 9 Frame Time Multiplexing Control transfers –Configuration, messages Bulk data transfers –High bandwidth, non-periodic Interrupt data transfers –Low bandwidth, response time sensitive Isochronous data transfers –Continuous, periodic, irregular data VideoAudioMouseKbdControlPrinterScanner Isoch.InterruptControlBulk 1 ms Frame

10. 10 Firewire (IEEE 1394) By Apple BW: –400 Mbps –800 Mbps for 1394b –Can send more than a CD every 10 sec Plug & play Support 63 devices Provides power Digital audio, video, external hard drives, …

11. 11 FireWire vs. USB 12Mbps 480 Mbps 800 Mbps USB 1.1 400 Mbps FW 400 USB 2.0 FW 800

12. 12 FireWire or USB? USBFireWire On-bus power2.5W45W (!) Max # devices12763 TopologyStarTree Plug & PlayYes Peer-to-peer connectivity NoYes Device CostLowHigh