Why Bus protocols should support 1024 bits, when processor are working with 64bits?

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arjun2145

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If the processors are working with 64bits, then why do they need Bus protocols to be as high as 1024bits.

Is it for re usability?
 

Higher transfer speed. Depending on the bus it can cause a serious slow down. If the bus on the circuit board or travels a long distance, then transfer speeds are in the MHz not GHz. So to move more data they need more lanes. This is kind of like parallel vs serial.

What bus are you referring to? I am guess memory.
 
arjun2145 said:
If the processors are working with 64bits, then why do they need Bus protocols to be as high as 1024bits.

Is it for re usability?
Click to expand...

It is only the address bus width of the processor that is limited to 64-bit but not the data bus width. For example, Cortex A8 has support for 128 bit data bus. Refer to the below link for details.

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0344h/ch09s02s02.html


Yes 1024 bits is for re usability + DMA transfer (DMA controllers generally custom designed by each company)
 

For Performance. Even if the CPU's registers are 64-bit, the cache lines will be wider.
 

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