TPMC917 User Manual Issue 1.0.7
Page 20 of 26
5.2 Big / Little Endian
•
PCI – Bus (Little Endian)
Byte 0
AD[7..0]
Byte 1
AD[15..8]
Byte 2
AD[23..16]
Byte 3
AD[31..24]
•
Every Local Address Space (0...3) and the Expansion ROM Space can be programmed to operate
in Big or Little Endian Mode.
Big Endian
Little Endian
32 Bit
32 Bit
Byte 0
D[31..24]
Byte 0
D[7..0]
Byte 1
D[23..16]
Byte 1
D[15..8]
Byte 2
D[15..8]
Byte 2
D[23..16]
Byte 3
D[7..0]
Byte 3
D[31..24]
16 Bit upper lane
16 Bit
Byte 0
D[31..24]
Byte 0
D[7..0]
Byte 1
D[23..16]
Byte 1
D[15..8]
16 Bit lower lane
Byte 0
D[15..8]
Byte 1
D[7..0]
8 Bit upper lane
8 Bit
Byte 0
D[31..24]
Byte 0
D[7..0]
8 Bit lower lane
Byte 0
D[7..0]
Figure 5-2 : Local Bus Little/Big Endian
Standard use of the TPMC917:
Local Address Space 0
32 bit bus in Little Endian Mode
Local Address Space 1
8 bit bus in Little Endian Mode
Local Address Space 2
not used
Local Address Space 3
not used
Expansion ROM Space
not used
