MPC823
NXP
MPC823 True Little-Endian Mode
Application NoteNxp
MPC8xx True Little-Endian Mode Application Note
An application note describing the implementation of True Little-Endian (TLE) mode in NXP MPC8xx processors to ensure compatibility with little-endian system agents.
Overview
This application note details the three endian modes supported by the NXP MPC8xx (including MPC823 and MPC860) processor families: Big-Endian (BE), PowerPC Little-Endian (LE), and True Little-Endian (TLE). It compares TLE mode with standard PowerPC address munging, explaining how TLE uses dedicated hardware for byte lane swapping to ensure data is stored correctly for external little-endian agents. The document describes the roles of the Load-Store unit, SDMA, SIU, and CPM in endian support and provides register configuration guidelines (MSR, DCCSTLES, FCR) and transfer examples for software development.
Use Cases
- Porting little-endian operating systems and applications to PowerPC-based systems.
- Designing embedded systems where MPC8xx processors must share memory with little-endian hardware agents or bridges.
- Configuring MPC8xx serial interfaces and SDMA for correct data ordering in little-endian environments.
Topics
NXP MPC823
NXP MPC860
PowerPC
True Little-Endian
Big-Endian
Byte Lane Swapping
Address Munging
SDMA
SIU
CPM
MSR
DCCSTLES
Referenced Parts
MPC860
NXP
as defined in the MPC860 PowerQUICC User Manual, the RTCSC register could be located at 0xFF000220
| MPC823 | NXP | MPC823 True Little-Endian Mode |
| MPC860 | NXP | as defined in the MPC860 PowerQUICC User Manual, the RTCSC register could be located at 0xFF000220 |