1. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Lab 3 – Differential Pair Synchronous communication (Physical Layer) Semester B, 2010 MPC8360 Computer Networks I 371-1-0201

2. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. The Open System Interconnection Reference Model (OSI) Physical Data Link Network Transport Session Presentation Application 1 1 2 2 3 3 4 4 5 5 6 6 7 7 We Are Still Here

3. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Noise ► So far we have considered only noiseless channels. ► This is obviously not the case in real life channels in which noise is always present. ► Noise is a random fluctuation in an electrical signal, it cannot be predicted.

4. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Noisy Channel Transmitter Noisy Channel Receiver 0 V -2 V 2 V Logic 0 Logic 1 0 V -2 V 2 V Logic 0 Logic 1 Data Data + Noise

5. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Wire A Some Sources of Noise ► Thermal noise Present due to the motion of the molecules in the conductor. ► Crosstalk Caused by inductive/capacitive coupling between two wires that are close to each other. Wire B 0 V 5 V Logic 1 Logic 0 bit flipped due to crosstalk

6. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Differential Pair ► A method of transmitting information electrically by means of two complementary signals sent on two separate wires. Transmitter Noisy Channel Receiver Data - Data Data + Noise - Data + Noise A BB A 0.5 [ A – B ] = 0.5 [ ( Data + Noise ) – ( – Data + Noise ) ] = 0.5 [ Data + Noise + Data – Noise ] = 0.5 [ 2 (Data) ] = Data 0 V -2 V 2 V Logic 1 0 V -2 V 2 V Logic 0 Assuming the Noise is equal in both channels

7. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Making the Noise equal Noise Source Blue wire receives most of the noise Both wires receive the same amount of noise Twisted Pair

8. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. USB - Universal Serial Bus ► The USB standard defines several physical interfaces ► USB signals are transmitted on a Twisted-Pair data cable ► The USB Standard was designed to transfer data & power.

9. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Ethernet ► Ethernet is a family of frame-based computer networking technologies for local area networks (LANs). ► It defines a number of wiring and signaling standards for the Physical Layer and Data Link Layer of the OSI networking model. ► Ethernet is standardized as IEEE 802.3. ► Ethernet is the most widespread wired LAN technology

10. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Ethernet physical layer ► The Ethernet standard defines several physical interfaces depending on the connection speed and/or distance. ► RJ 45 Connector ► Unshielded Twisted Pair (UTP) ► Shielded Twisted Pair (STP or STP-A) ► Category 3 (cat3) - 100 Mbit/s Category 5 (cat5) - 1000 Mbit/s Category 5 (cat5) Category 3 (cat3)

11. TM Freescale Confidential Proprietary Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. Quick Overview