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GT-96100A Advanced Communication Controller
464
Revision 1.0
25.1.1
Bit 12 of the CPU Interface Configuration register
Bit 12 of the CPU Interface Configuration register (0x000) affects the following:
Setting this bit to 1 (Little-endian mode) means there is no byte swapping within the CPU Interface unit
on any data transfer.
Setting this bit to 0 (Big endian mode) means that byte swapping takes place on data transfers
from CPU to the GT-96100A internal registers (including Configuration Data register, offset 0xcfc). No
byte swapping takes place on data transfers for which the source/target is external.
25.1.2
Bits 0 and 16 of the PCI Internal Command register
Bit 0 of the PCI Internal Command register (0xc00) controls byte swapping of GT-96100A PCI master interface.
Bit 16 controls byte swapping of GT-96100A PCI target interface. These bits affect the following:
Setting these bits to 1 means there is no byte swapping within the PCI Interface unit on any data transfer.
Setting these bits to 0 means that no byte swapping takes place on data transfers from PCI to/from the
GT-96100A internal registers. Byte swapping does take place on data transfers for which the source/tar-
get is external
25.1.3
Bits 10-12 of the PCI Internal Command register
Setting these bits to 0 means there is no word swapping.
Setting these bits to 1 means that no word swapping takes place on data transfers from PCI to/from the GT-
96100A internal registers. Word swapping does take place on data transfers for which the source/target is exter-
nal.
NOTE: Only the 32-bit PCI interface supports word swapping.
Table 429: Nomenclature
Name
Definition
W, Word
32-bits of data, R4600 terminology
DW, Double Word
64-bits of data, R4600 terminology
Even Address
Address of which A[2] == 0
In Little-endian format, this address points to the LEAST significant W of a DW.
In Big-endian format, this address points to the MOST significant W of a DW.
Odd Address
Address of which A[2] == 1.
In Little-endian format, this address points to the MOST significant W of a DW.
In Big-endian format, this address points to the LEAST significant W of a DW.
Even Word
LEAST significant W of a DW.
Odd Word
MOST significant W of a DW.