1) In Booth's bit-pair recording technique how to multiply a multiplicand with 2?
2) In booth's algorithm for multiplication/Booth's bit-pair recording of multipliers, the sign bit extension of the multiplicand i.e. we must extend the sign-bit value of the multiplicand to the left as far as the product will extend. Now my question is what should be the value of extended Sign Bit?
I think following are the possible values-
Multiplier Bit, Extended sign bit value
i) 0, 0
ii) +1, 0
iii) -1, 1
iv) -2, 1
v) 2, I don't know
Also, why is the sign bit extended? Will we get the correct answer if we don't extend sign bit?