NANOSCALE STANDARD DIGITAL MODULES - Bio-Inspired and Nanoscale Integrated Computing - page 251

TABLE 9 . 5 . Frequency Assignments in the First Method of
Binary Decoder Implementation
Node Sending frequency Receiving frequency

Binary inputs f adc -

Analog input f sel f adc

Outputs - f sel

frequency of this analog input node is determined depending on the method we
choose for implementing the decoder.
In the first method, the input node broadcasts the index of the output it is
selecting on a common frequency, f sel , at which all the output nodes are tuned. In
this implementation, all the output nodes are required to know their index. They
receive the broadcasted value, compare it to their index, and the one whose index
has been broadcasted outputs 1. Table 9.5 shows the sending and receiving
frequencies the nodes have to be tuned on.
In the second method, the output nodes do not need to have any information
regarding their indices. Instead, a distinct frequency is assigned to each output
node. For instance, output i is tuned on f i . The input node, which contains the
index of the output node, sends a signal on the specific frequency assigned to that
output. The output node that receives this signal outputs 1. Since the output nodes
are tuned on distinct frequencies, only one output node receives this signal.
Table 9.6 shows the frequency assignments for the second method of implement-
ing a spin-wave binary decoder.
Binary decoders are widely used in different logic systems. One of their most
important applications is in decoding the address when accessing memory cells.

9.3.4. Nanoscale Spin-Wave Multiplexer
A multiplexer is a device that selects one of many data sources and outputs that
source into a single channel. In other words, multiplexers function as multiple-
input, single-output switches. A 2 k -input multiplexer is a combinational system that
has 2 k binary inputs, k binary control (select), and one data output. The output of
the multiplexer is equal to the data input selected by the control input [1].

TABLE 9 . 6 . Frequency Assignments in the Second Method of
Binary Decoder Implementation
Node Sending frequency Receiving frequency

Binary inputs f adc -

Analog input Variable (f i ) f adc

Output i - f i