M16C6S_09 Datasheet, PDF (199/208 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6S Group
APPENDIX
APPENDIX
IT800DLL Explanatory Note
June 2, 2005
IT800 Data Link Layer – Functionality and Advantages
1. Scope
This document describes the functionality of the Data Link Layer (DLL) implemented in the products
based on Yitran's IT800 technology for narrowband networking using the power line wiring.
The purpose of this document is to emphasize the advantages of the embedded algorithms and mecha-
nisms of the DLL and to analyze the scenarios of using other implementations of a Data Link Layer.
2. Network Reference Module
The DLL is the 2nd layer of the 7 layers in the OSI network reference model illustrated in Figure 1(a).
According to this model, data is transported upstream and downstream between subsequent layers,
where the communication between layers of different communication nodes is basically carried out be-
tween the same layers [Figure 1(b)].
Application
Presentation
Session
Transport
Network
DLL
PHY
Upper Layers
Physical Layers
Data
Transport
Layer 3
Layer 2
Layer 1
Layer
Communication
STOP
Layer 3
Layer 2
Layer 1
(a) OSI 7 Layers Model
(b) Data Transport and Layer Communication
Figure 1: Network Reference Model
The Physical Layer (PHY) defines the electrical specifications for activating, the physical link between the
communicating network system nodes. The DLL algorithms are designed to establish and manage a
unique access channel between any two nodes as optimally and fairly as possible while minimizing the
probability of collisions.
The IT800 DLL was developed by Yitran especially for the IT800 PHY and using the DLL optimize the
utilization of the PHY and thus optimizes the overall performance.
The IT800 DLL implementation manages the time critical sessions of the interface with the PHY and uses
the knowledge of the PHY implementation for optimal interrupt decoding and efficient interface interac-
tions. The DLL takes advantage of various PHY features such as multiple transportation modes and the
ability to create special packets and signals, enabling optimal utilization of the media channel while pro-
viding the most reliable data transfer.
Copyright © 2005, YITRAN Communications Ltd.
Rev.5.01 Dec 10, 2009 page 199 of 201
REJ03B0014-0501