PXD20RM Datasheet, PDF (1311/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Chapter 38
Run-Length Encoding Decoder (RLE_DEC)
38.1 Introduction
The RLE_DEC module is used to decode data that has been compressed using a Run Length Encoding
(RLE) scheme. It has input and outputxs FIFO buffers directly connected to the crossbar switch and
requires the CPU or DMA to push in the encoded data and then extract the decoded result. The module
configuration is optimized for decoding data stored in a two-dimensional image format but can also be
used to extract data stored as a linear array.
RLE_DEC
Crossbar switch
DMA
FIFO
Fill
Levels
Rx and Tx FIFO Busy
thresholds Status
IP Bus
REGIF
Pixel
Width
Busy
Status
AHB CTRL
Read
Interface
Write
Interface
T
X
F
I
F
O
Write
Interface
R
X
F
I
F
O
Read
Interface
FSM
AHB Bus
Figure 38-1. RLE_DEC block diagram
38.1.1 Overview
Figure 38-1 is a block diagram of the Run-Length Encoding Decoder (RLE_DEC) module. The module
has two independent interfaces that are memory mapped into the device:
• Crossbar switch interface for moving data into and out of the module
Freescale Semiconductor
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
38-1