Big / Little Endian
5.3
•
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]
Table 5-2 : Local Bus Little/Big Endian
Standard use of the TPMC316:
Local Address Space 0
16 bit bus in Little Endian Mode
Local Address Space 1
not used
Local Address Space 2
not used
Local Address Space 3
not used
Expansion ROM Space
not used
To change the Endian Mode use the Local Configuration Registers for the corresponding Space. Bit
24 of the according register sets the mode. A value of 1 indicates Big Endian and a value of 0
indicates Little Endian.
TPMC316 User Manual Issue 1.2.1
Page 17 of 20
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