Figure 3.2: Two types of multiplier: (a) Scaled addition and (b) Scaled
subtraction in SC
where var(pˆi) = σ2 (pˆi) , i
= 1, 2, σ (pˆi) calculated as
(1.6).
Besides, a stochastic scaled subtraction can be carried out with a small
change as illustrated in Fig.3.2b.
In this configuration, a NOT gate is used to perform the
subtrahend p2. It can be writen as
pout = s.p1 + (1
− s).(1 − p2) (3.5)
Note that this operator only works for the bipolar representation.
Therefore, by assuming p1b , p2b ,
poutb are the bipolar formats corresponding to the unipolar ones
p1, p2, pout,
(3.5) can be become the expected
scaled subtraction
poutb = s.p1b − (1 − s).p2b .
(3.6)