MPC5510 Microcontroller Family Reference Manual, Rev. 1
Freescale Semiconductor
33-1
Preliminary
Chapter 33
Media Local Bus (MLB)
33.1
Introduction
The Media Local Bus (MLB) is an inter-chip communication bus that gives external devices real-time
access to the Media Oriented Systems Transport (MOST) bus. It has been designed to standardize a
common hardware interface and common software API library, and allows transport of synchronous,
asynchronous, isochronous and control data. The standardization allows an application (or multiple
applications) to access the MOST network via a MOST transceiver. An MLB system consists of one MLB
controller and one or several MLB devices. The MLB controller is typically an Intelligent Network
Interface Chip, for example, the INIC/OS81050 (INIC), which functions as a transceiver for the MOST
network and as a controller for the Media Local Bus.
The MLB interface consists of an MLB clock (generated by the MLB controller), MLB signal, and MLB
data lines. There are two possible interface configurations: 3-pin and 5-pin. In the 3-pin interface, the
MLBSIG and MLBDAT are bidirectional and the MLBCLK is unidirectional. In the 5-pin interface, all
signals are unidirectional (MLBSI, MLBSO, MLBDI, MLBDO, and MLBCLK).
The MPC551xE/G implements a software
1
emulated MLB solution (SoftMLB) that is based on the
e200Z0 core (IOP), but also uses system RAM, 2xDSPIs, and the eDMA module. In addition, SoftMLB
Interface Logic has been integrated to detect the
FRAMESYNC
pattern and generate the appropriate
triggers to the IOP, eDMA, and DSPIs. The MLB signals are routed out on Port E and Port F, which are
on VDDE1 and VDDE3 power domains respectively. The MLB signals on Port E must be externally level
shifted to be compatible with the 2.5 V MLB bus (as the VDDE1 domain must be 5 V to cater for other
signals on this domain). The VDDE3 is a smaller domain that is shared with Nexus, JTAG, and some EBI
signals.
33.1.1
Block Diagram
is a simplified block diagram of the SoftMLB concept and shows the functionality and
interdependence on the other major blocks in the SoC.
1. A software driver for MLB emulation will be available from freescale. Available date - TBD