# WAGSR

## a tool for generalized feed forward shift registers

a tool for generalized feed forward shift registers

### What is WAGSR?

What is WAGSR?

WAGSR (Web Application for Generalized feed forward Shift Registers) is an web application program to compute/solve various problems on GFFSR (Generalized Feed Forward Shift Register) by symbolic and logic simulation as follows.

- Design of GFFSR by means of logic expressions
- Illustration of GFFSR
- Computation for GFFSR
- Symbolic simulation
- Logic simulation by partially specifying values 0, 1, and/or X to input/output sequence, initial state, and/or final state.

### What is GFFSR?

What is GFFSR?

GFFSR is a circuit with the form shown in this figure. It is a generalized form of linear feed forward shift registers. In this figure, f1, f2, ..., fk are arbitrary logic functions.

### How to use WAGSR

How to use WAGSR

WAGSR is a Web application. You can use it from the following URL.

To use it, SVG Web browser is necessary. (Internet Explorer 9 or later, Firefox 1.5 or later, Safari 3 or later)

1. Design of GFFSR by means of logic expressions

- Circuit Designer button: Start the design of a new circuit.
- Stage field: Enter the number of flip-flops
- “by expressions” tab: Enter the logic expressions in JavaScript form.
- Available operators:

- “Transform into ~” button: The logic expression is transformed into Reed-Muller canonical form or CNF.
- Circuit with feed-back can also be defined, but computation cannot be done.
- “by XOR connection” tab: circuit with XOR connection only can be designed easily by using ON/OFF of connections. (a tool specialized to linear circuits is open to the public
**SREEP**)

2. Illustration of GFFSR

3. Computation for GFFSR

- “Info” tab: illustrate basic information
- “Variable” tab: symbolic simulation
- “Calc” tab: logic simulation by partially specifying values 0, 1, and/or X to input/output sequence, initial state, and/or final state. If inconsistency occurs, it becomes red.

### References

References

- Katsuya Fujiwara and Hideo Fujiwara, "WAGSR: Web Application for Generalized Feed Forward Shift Registers," 13th IEEE Workshop on RTL and High Level Testing (WRTLT'12), pp. 1.2.1-1.2.7, Nov. 2012.
- Katsuya Fujiwara and Hideo Fujiwara,"Generalized Feed Forward Shift Registers and their Application to Secure Scan Design," IEICE Trans. on Inf. and Syst., Vol. E96-D, No. 5, pp. 1125-1133, May 2013.