PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor 27-1
Chapter 27
Media Local Bus (MLB)
27.1 Introduction
The MediaLB (MLB) is a multiplexed bus protocol defined by Standard Microsystems Semiconductor
Company (SMSC) to transfer multimedia data between the Media-Oriented Systems Transport (MOST)
ring and supporting system level ICs. It supports the complete MLB specification. This module offers a
serial to parallel conversion of the 3-pin MediaLB signals into 32-bit parallel words and vice versa for
transfer to system memory. This module provides a MediaLB port for all MediaLB relevant signals and
an application port to interface to the PXN20. The application port incorporates all signals necessary to
access MediaLB data bytes and protocol information as well as signals for controlling MediaLB Device
Core functionality.
NOTE
The MLB block is not implemented on the PXN20.
27.1.1 Block Diagram
A block diagram of the MLB module can be found in Figure 27-1.
Figure 27-1. Block Diagram
Channel Arbiter
Channel Buffer
Link Logic
Configuration Logic
MLB Core
Clock and Reset Logic
MLBDAT
MLBSIG
MLBCLK
Host Bus
Peripheral
Bus
Local Buffer RAM