Final presentation of the design

Final presentation of the design.

In this advance, all of the objectives have been completed and the presentation is here. Also you can download the .jelib file which contains the design in electric format and the library used.

It can be access by Google Docs. https://docs.google.com/presentation/d/1XAxohRVTJGIdE1dUHGC7QcliQiZqaxDNq-5RChTOqa8/pub?start=false&loop=false&delayms=3000,

and also the file of VLSI Electric is available in this link: https://drive.google.com/file/d/0B6RLCqU_0rjGcHhUUlFNRG5jUk0/edit?usp=sharing


That is funny since until this point there is a half of the job because still is necessary to analyze both the electrical effort and the logical effort.


Here you will see simulations and foundations.

Fourth Advance: Improvement 3to9

Fourth Advance: Improvement 3to9

Hello again, in this advance we got the feedback from a professor that the crossbar would be better if it had 9 outputs instead of 8, in order to get 3 differents ways at the same time. So that's why in this advance you're gonna see another output and other control signal too. 

Also, the layout view was already made and the icon view too, it is better if we don't upload the .jelib file yet because there are some mistakes that we have to solve, for examples some exports and trifles

In this picture you'll see the new schematic design.

As you can see, the format of this picture is block view, that's because the saturation of transistors is too much. At the right side we put the new bar, the nineth. 

Now, the control signals can be asserted every two signals, for example:

S0=1,  S1=0, S2=0, S3=1, S4=0; S5=0; S6=1, S7=0, S8=0.   Of course, it is not necessary to assert more than one, but it is imposible to assert more than three (if you do, bye bye crossbar).

The next picture shows the layout view.

 This is just a part of the design, all of the design is too much saturated and it wouldn't be understandable.

Finally, whatch the icon view, it is really cool and makes a better idea of the full design.

At this moment the hanging jobs are: simulation, summary of costs and surface, maximum frequency.

Third Advance: First diagram with Electric VLSI

First Diagram: Icon view.

It is important to know that Electric enables you to create differents views, diagrams and representations for the same cell. Basically we are going to use the schematic, icon and layout view for this project. 

In this advance we are gonna show you the icon view in order to get a better interpretation of the crossbar, and also we are gonna show you the schematic view.

This Figure shows the electric diagram of the crossbar by using ic blocks. 

As you can see, we just need some inverters, and 24 pass gates, in this case buffers tri_state. There are a lot of wires connecting all of the elements, but remember that just three buffers are gonna to turn on once, so the electric effort is not too much.

Now, you can see the schematic view, in this case we're gonna show you two images because the saturation of elements makes it difficult to understand.

This Figure shows a schematic view by using blocks representation, every block means a certain element, so it is easy to see the device in a general representation.

In other hand, this Figure shows a part of the schematic view by allowing the transparency of the blocks, so you can see inside of every block, and the connections. Don´t worry about the icon of every block, that is part of the view but isn´t an element, it is just for clarify what the group of transistors means.

Still, it is missing the layout view, that's because it requires more job, so be patient.

Second Advance: Electric VLSI Design System

Second Advance: Electric VLSI Design System

The application that it's going to be used is "Electric VLSI Design System", from Static Free Software.

This application has many capabilities, since you can make the schematics designs, layout designs and icon views, until you can run many tests in order to verified the composition of yours designs. Tests about analog behavior with spice codes, digital behavior, minimal distances of the layout, crosstalk effects, also it can read files from netlists and verilog codes and so many other functions. 

It can be downloaded by: http://www.staticfreesoft.com/

This is the introduction of the program copied form the user help:

Now you have it!
A state-of-the-art computer-aided design system for VLSI circuit design. Electric designs MOS and bipolar integrated circuits, printed-circuit-boards, or any type of circuit you choose. It has many editing styles including layout, schematics, artwork, and architectural specifications.
A large set of tools is available including design-rule checkers, simulators, routers, layout generators, and more.
Electric interfaces to most popular CAD specifications including EDIF, LEF/DEF, VHDL, CIF and GDS.
The most valuable aspect of Electric is its layout-constraint system, which enables top-down design by enforcing consistency of connections.
This manual explains the concepts and commands necessary to use Electric. It begins with essential features and builds on them to explain all aspects of the system. As with any computer system manual, the reader is encouraged to have a machine handy and to try out each operation.         

So, this advance is really important in order to make an overview of the tools that are going to be used throughout the project.

Description of the project: Crossbar 3 to 8

Main description of the project.

The following document stands in order to show you a basic design of a crossbar with 3 inputs and 8 outpus. For now it's standing in the way the logic control, so you will suppose that any control signal is ok.

The general rules and objectives.

The task is to generate the physical design of digital logic module architecture investigating micro architecture and design. Producing such module in the electric tool in view of symbol, schematic and layout. Produce electrical simulations of the logical operation and maximum dynamic performance of the module; submit a written report and make an oral presentation of the design and implementation stages of the circuit.

1) Provide a block diagram representing the logical operation of the device (10 % ).

2) Investigate at least 2 different architectural implementations for module design and     justify why they chose that you implement (10 % )

3) Present the schematic diagram of the module (10 % )

4 ) Submit the completed layout of the module (20 % )

5) Provide a functional simulation 1 use case for the module (10 % )

6) Submit an electrical simulation show the maximum frequency of operation of the module ( 20 % )

7) Prepare a 20 minute demonstration for the class of your module and design ( 10%)

8) Include in the report the following information:

• Total area of the circuit.
• Count cells by cell type.
• Levels of metal used.
• Optimizations if any, would.

Comment on the main difficulty of the project.

First advance.

After to review the specs and functionality of the crossbar, it is a circuit that implements a kind of bit's rotator because the three inputs are going to be rotated according to the control signal asserted. The Figure 1 shows a preview.

First circuit design: S1,S2...S7 are control signals. X0,X1,X2 are inputs and Y0,Y1...Y7 outputs.

As you can see, this is a very simple design with only uses pass gates and ports, wires, and maybe some invertes for improving the exterior signals. The mapping table can be seen in the Table1.

Table1: Mapping table.

S7	S6	S5	S4	S3	S2	S1	S0	|	Y7	Y6	Y5	Y4	Y3	Y2	Y1	Y0
0	0	0	0	0	0	0	1	|	Z	Z	Z	Z	Z	X2	X1	X0
0	0	0	0	0	0	1	0	|	Z	Z	Z	Z	X2	X1	X0	Z
0	0	0	0	0	1	0	0	|	Z	Z	Z	X2	X1	X0	Z	Z
0	0	0	0	1	0	0	0	|	Z	Z	X2	X1	X0	Z	Z	Z
0	0	0	1	0	0	0	0	|	Z	X2	X1	X0	Z	Z	Z	Z
0	0	1	0	0	0	0	0	|	X2	X1	X0	Z	Z	Z	Z	Z
0	1	0	0	0	0	0	0	|	X1	X0	Z	Z	Z	Z	Z	X2
1	0	0	0	0	0	0	0	|	X0	Z	Z	Z	Z	Z	X2	X1
								|
	Control Inputs							|		Data Outputs

It is intended to use the manhattan distribution for the layout design, but that is for the next advance. Also, I will recommend to read the next document, it is an extract to a very cool book and explain this very good: Chapter9.

References:

•  Notes of the Microelectronic course at Electrical Engineering School, UCR, Costa Rica.