how to determine - how many bit processor

[scorrpeio]

This question seems to be weird but I have confusion about it...how can I determine whether a processor is 8,16 or 32 bit?

Even I have searched on google and this website as well. But everyone had their own opinion which is baffling me...

1. The no of bits ALU can process at a time
2. Data width
3. Internal Register width
...etc

I had knowledge that the ALU would determine the bit size of processor. But, then
how to determine how many bit processor is dual core/multicore processors are?

Also, how many bit processor is BF561?

Can anyone tell, which parameters to be considered and on which priority to determine how many bit is our processor??

 

[Jack// ani]

All of the three options are correct.

Internal register width, determines number of bits a processor is capable of handing at a time. Register width in turn dictates data bus width, and number of bits ALU can process in single go.

8-bit processor can very well process 16 & 32-bit data, but not necessarily in a single cycle.

 

[FvM]

how can I determine whether a processor is 8,16 or 32 bit?

I'm tempted to ask what's the purpose of this question? A processor with a set of 32-bit GP registers and a 32-bit datapath and ALU would be usually recognized as 32-bit processor. As far as the BF561 is used as general purpose processor, it plays the role of a 32-bit processor. In DSP applications - depends on. This point raises doubts about the sense of general classifications.

 

[scorrpeio]

@Jack//ani
Thank you for sharing info

@FvM
I am asking the question because, many a times it is asked in interview. So, I must be clear of how to answer such a basic question.
Well, about BF561, there is still an ambiguity, as some experts call it as 16 bit processor.