Q: Big or little endian, which is best?
A: The answer depends on what level you are working:
Example: Assuming binary numbers are stored as 16 bits, and that you want the following data in the memory:
- 513 starting at address 0
- "abcd" starting at address 2
- 1027 starting at address 6
High level: If you're working with text files and want the text to display in the right order...
... then you like LTR (left-to-right) dumping and hence big-endian looks better:
|
Byte number (Byte address)
|
0
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
|
The data from the example:
|
513
|
"a"
|
"b"
|
"c"
|
"d"
|
1027
|
Advantage: texts like "abcd" comes in the right order.
|
|
Bytes
|
0x02
|
0x01
|
|
|
|
|
0x04
|
0x03
|
Big endian looks better.
|
Bit value
Bit order as they appear in memory
Bit address within 16-bit number
|
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
0
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
|
|
|
|
|
0
|
0
|
0
|
0
|
0
|
1
|
0
|
0
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
1
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
Drawback: The bits comes in the wrong order.
|
Low level: If working with registers and want the bits of a word to display in right order...
...then you want RTL (right-to-left) dumping and little endian:
|
Byte number (Byte address)
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
The data from the example:
|
1027
|
"d"
|
"c"
|
"b"
|
"a"
|
513
|
Drawback: texts (like "abcd" above) comes in the wrong order.
|
|
Bytes
|
0x04
|
0x03
|
|
|
|
|
0x02
|
0x01
|
Little endian looks better.
|
Bit value
Bit order as they appear in memory
Bit address within 16-bit number
|
|
0
|
0
|
0
|
0
|
0
|
1
|
0
|
0
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
1
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
|
|
|
|
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
0
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
15
|
14
|
13
|
12
|
11
|
10
|
9
|
8
|
|
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
7
|
6
|
5
|
4
|
3
|
2
|
1
|
0
|
|
Advantage: The bits comes in the right order.
|
Summary (of my opinion)
I my opinion, one of the most important thing is that the tool you use to view the data allows you to switch between LTR/RTL viewing.
What you really are doing is mixing LTR data with RTL data. Depending on which you think dominates, you may come to different conclusions of which is best.