Talk:16-bit

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Hello Friends.

Can any body explain a little that what is the basic difference between 16-bit and 32-bit words. I just want to know that what is the actual advantage of 32-bit word over 16-bit.

regards

Raheel

Sure.

It's basically like this. If the word size of a machine is 16-bit, then you can store at most 2^16 = 65536 different combinations in one word. These combinations are often taken to be the numbers 0 to 65535 or -32760 to 32759 or memory locations.

If you need larger numbers, or if you need to keep track of more data that needs more memory, you'll need to use two words.

Using two words for storing numbers increases the time it takes to do calculations with them. This is because instead of one operation to for instance add two numbers, more operations are needed.

If you use a 32-bit machine however, you can use 4294967296 different combinations. That means you can use a single word to contain larger numbers or references to a wider range of memory locations.

Therefore a 32-bit machine will perform better at the same clock speed, with the added bonus of making the lives of programmers easier. (The last bit has also got a lot to do with the way some processor manufacturers (Intel springs to mind) and OS developers (Microsoft for instance) chose to overcome the restrictions of 16-bit words.)

I hope this helps.

Yours sincerely,

Shinobu 07:12, 31 August 2005 (UTC)

16-bit DOS and Windows 1.0/2.0 applications

Those applications were 16-bit, not 8-bit. The 8088 was a processor with a 16-bit instruction set and an 8-bit bus; it's the instruction set, not the bus width, that matters to the "width" of applications. Guy Harris (talk) 18:56, 20 January 2008 (UTC)

Memory Adressing

So how many kilobytes can 16 bit processor address?--169.232.119.28 (talk) 02:11, 1 May 2008 (UTC)

From looking at this and other pages, it appears it can address 2¹⁶ = 65536 bits, which is 8192 bytes (octets) or 8 kibibytes. If by "kilobyte" you mean "1,000's of bytes," then it's 8.192 KB, but if you meant "1,024's of bytes," which is what Windows and I think Macintosh now use, then it's 8 KiB. Eebster the Great (talk) 05:04, 14 September 2008 (UTC)

Its actually 65,536 bytes, which is 64 kilobytes. Using certain techniques, a CPU can address more memory than the width of its ALU. An example of this would be the Intel 8086, which is a 16-bit microprocessor with a 20-bit physical address capable of addressing 1 megabyte. Rilak (talk) 07:58, 14 September 2008 (UTC)

Eebster made the assumption that every single bit has its own address, but addressing is done per byte. Therefore Eebster was a factor eight off. Shinobu (talk) 03:03, 4 October 2008 (UTC)

Good call; sorry. I guess I'll try restrict myself to answering questions to which I actually know the answer. Eebster the Great (talk) 05:12, 4 October 2008 (UTC)

But if we stuck with what we already know, how would we ever learn anything? I agree that, with a flat memory model, 16 bit addresses can be used to specify at most one of 2¹⁶ = 65536 addressable locations. With byte-addressable memory, that gives 64 KiB. But some 16 bit digital signal processors use 16 bit word addressable memory, and so they can directly address the equivalent of 128 KiB. However, some systems don't have a flat memory model -- as Rilak implied, some systems have hardware that uses bank switching or memory segmentation to allow the CPU to indirectly address significantly more memory. —Preceding unsigned comment added by 68.0.124.33 (talk) 20:20, 24 October 2008 (UTC)

Good point! I think we should clarify the article, and perhaps all n-bit articles. Rilak (talk) 08:48, 25 October 2008 (UTC)

Shouldn't the Z80 and the 6809 go here since you still consider 68000 as being 32-bit?

You always consider 68000 being 32-bit for no other reason other than it's registers being 32-bit, regardless of it having a 16-bit ALU and data bus, but you never call the Z80 and the 6809 16-bit, despite them having the same reasoning? —Preceding unsigned comment added by 75.57.174.145 (talk) 16:06, 16 May 2009 (UTC)

Add list of 16-bit CPUs/MPUs?

I believe that it would be beneficial to have a consolidated list of 16-bit CPUs and MPUs on this page, much like the 8-bit page's list. This would make it very easy for readers to browse through all the 16-bit architectures and processors without having to fish around. Therefore, I am adding an incomplete list to this article with the processors and architectures I am aware of. If there is a more preferable way to do this, or if you know of something to add to the list, please feel free to help. Daivox (talk) 03:10, 3 May 2011 (UTC)