A microprocessor provides an instruction capable of moving a string of bytes from one area of memory to another. The fetching and initial decoding of the instruction takes $20$ clock cycles. Thereafter, it takes $25$ clock cycles to transfer each byte. The microprocessor is clocked at a rate of $20$ GHz$.$

a$.$ Determine the length of the instruction cycle for the case of a string of $"128$ bytes".

b$.$ What is the worst$-$case delay for acknowledging an interrupt if the instruction is non$-$interruptible?

c$.$ Repeat part $($b$)$ assuming the instruction can be interrupted at the beginning of each byte transfer.