PNX1500E NXP Semiconductors, PNX1500E Datasheet - Page 801

• Manufacturer Part Number: PNX1500E
• Manufacturer: NXP Semiconductors

Specifications of PNX1500E

• Lead Free Status / Rohs Status: Not Compliant

1. Introduction
1.1 Features
Two addressing conventions exist in the computer industry: little-endian and
big-endian.
The PNX15xx/952x Series supports both big-endian mode and little-endian mode,
allowing it to run either little-endian or big-endian software, as required by the
particular application.
This chapter explains the concepts and programmer’s view of data structures
required for module control and module DMA. The chapter also contains a section
that shows how hardware modules, buses and bridges implement the programmer’s
view.
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Chapter 29: Endian Mode
PNX15xx/952x Series Data Book – Volume 1 of 1
Rev. 4.0 — 03 December 2007
In the little-endian convention, a multi-byte number is stored in memory with the
least significant byte at the lowest memory address, and subsequent bytes at
increasing addresses.
In the big-endian convention, the most significant byte is stored at the lowest
memory address, and subsequent bytes are stored at increasing addresses.
The PNX15xx/952x Series supports big-endian and little-endian operation.
The system as a whole (all CPUs and all on-chip DMA modules) must operate in
the same endian mode.
When used with an external CPU, the PNX15xx/952x Series must operate in the
same endian mode as the external CPU. If the endian modes between the
external CPU and the PNX15xx/952x Series are different, then the external CPU
must be aware of this difference and appropriately handle all data swapping.
The endian-mode choice is made at boot time. It can be changed by software, but
this requires a partial system reset.
Product data sheet