main coding difference b/w Big-endian and Little-endian

[anusha vasanta]

Hi all,
here i was taking my reg as
reg [7:0] data [63:0] this is a big endian then what is the difference b/w reg [0:7] data [63:0] is this also a big endian or the representation is not correct? clear this doubt
thanx in advance

 

[sharath666]

Big endian or little endian has nothing do with your RAM or array definition. It is the way you access data. Assume a 32bit data is accessed bytewise. Depending on whether your system is big or little endian ,you will access bits[7:0] first or bits[31:24]..

 

[std_match]

The big/little endian property applies to more than one level.

The most common "problem" is the byte order.
An example, the value 0x1234 (hexadecimal in C-style)
The bytes are stored in the following order in a little-endian machine: 0x34 0x12
In a big-endian machine. 0x12 0x34

It is easier for a human to read a big-endian byte hex dump, but from a hardware/software standpoint I prefer little-endian.

The we have endianness on the bit level (bit numbering within a byte/word).
The strict big-endian machines, like PowerPC, say that the highest bit is bit 0.
I think that is crazy. I can't see any advantage at all, only problems.

There are mixed-endian architectures like the 68000 serier. Big-endian in the byte level but "normal" little-endian bit numbering witing words.

The Intel processors used in PC's are little-endian.