NANOSCALE STANDARD DIGITAL MODULES - Bio-Inspired and Nanoscale Integrated Computing - page 250

Binary outputs

y k − 1 y 0

...

x 0

N = 2 K

A/D

Input

y 0

Analog
out

x 0 x 1

x N − 1

x i

y i

x i

... ...

y k − 1

i

x N − 1

Binary encoder

Figure 9.5. Structure of a nanoscale spin-wave binary encoder.

the output node based on several reference voltage thresholds. The digitized value
will be k= log N bits which are the outputs of the binary encoder.

9.3.3. Nanoscale Spin-Wave Binary Decoder
A k-input binary decoder is a combinational system that has k binary inputs and
2 k binary outputs. The inputs represent an integer in the range of 0 2 k 1 [1].

In other words, assuming N=2 k , the binary decoder has N outputs and k= log N
inputs. A spin-wave binary decoder consists of k input and N output nodes
connected to a spin-wave bus. We show two different methods for implementing a
nanoscale binary decoder using spin waves. The structure of a spin-wave decoder
that has been implemented based on these two methods is shown in Figure 9.6.
In both designs, the binary input value is first converted to analog using a
digital to analog converter. An additional node, which is in fact the output of
the digital to analog converter, stores the analog value of the input represented by
the log N bit inputs. To find this analog value, the binary input nodes send their
value (i 2 i ) on frequency f adc . The analog input node's receiving frequency is
tuned on f adc and it receives the index value. At the next step, the sending

y

Analog
input

N=2 K Inputs Outputs

x k − 1 x k − 2 y N − 1

x 0 X y 0 y 1 y 2

x 0

... ...

y 0

f sel
f i

1
2

y i

x i

y N − 1

Digital to analog
converter

Decoder

x N

−

1

Figure 9.6. Structure of a nanoscale spin-wave binary decoder.