Endian Modes - Motorola MPC823e Reference Manual

SECTION 14

ENDIAN MODES

This section will discuss how the MPC823e supports three system endian configurations:
• Little-endian system
• Big-endian system
™
• PowerPC little-endian system
A general description of the different endian modes can be found in The PowerPC
Microprocessor Family: The Programming Environments (MPCFPE/AD) manual that is
available from Motorola. Throughout the MPC823e Reference Manual , the term system
refers to the devices that reside on the MPC823e bus. The MPC823e core operates in the
big-endian mode of a big-endian system and in the PowerPC little-endian mode of two other
configurations.
Table 14-1. Little-Endian Effective Address Modification
DATA LENGTH (BYTES)
NOTE:
Table 14-2 contains possible programming configurations.
Table 14-2. Endian Mode Programming For Core Data Structures
MODE
Big-Endian Mode
Little-Endian Mode
PowerPC Little-Endian Mode
Reserved
MOTOROLA
For Individual Aligned Scalar
ADDRESS MODIFICATION
1 XOR with 0b111
2 XOR with 0b110
4 XOR with 0b100
8
There are no 8-byte scalars in the MPC823e .
MSR (AND MSR
LE
0
0
1
1
MPC823e REFERENCE MANUAL
(No Change)
) DC_CSR
ILE LES
0
1
0
1
14-1