Little Endian

BYTE 3

BYTE 2

BYTE 1

BYTE 0

BYTE 0

BYTE 1

BYTE 2

BYTE 3

31 0

Second Cycle

First Cycle

15 0

BYTE 0 BYTE 1

15

Big Endian

BYTE 0 BYTE 1

15 0

Big Endian

Big Endian

Figure 2-5. Big/Little Endian—32-Bit Local Bus

Figure 2-6. Big/Little Endian—16-Bit Local Bus

2.2.5.3 8-Bit Local Bus—

BYTE 3

BYTE 2

BYTE 1

BYTE 0

Big Endian Mode 31

For an 8-bit Local Bus, the PCI 9030 can be programmed to use upper or lower byte lanes.

Little Endian

Second

First Cycle

Table 2-13. Upper Byte Lane Transfer— 8-Bit Local Bus

Fourth Cycle

31 24

Burst Order	Byte Lane
First Transfer	Byte 0 appears on Local Data [31:24]
Second Transfer	Byte 1 appears on Local Data [31:24]
Third Transfer	Byte 2 appears on Local Data [31:24]
Fourth Transfer	Byte 3 appears on Local Data [31:24]

BYTE 0

Third Cycle

23 16

BYTE 0

7 0

Cycle

15 8

BYTE 0

7 0

7 0

BYTE 0

7 0

Big Endian

7 0

Figure 2-7. Big/Little Endian—8-Bit Local Bus

Дата добавления: 2015-07-10