Click on File-> New in order to restart the software with an empty screen. The current design should be saved before asserting this command, as all the graphic information will be physically removed from the computer memory. No Undo is available to disable the New command.
Click on the above icon. In the list, double-click on the file to load. " .SCH " is the default extension that corresponds to the schematic files.
Click on File -> Save to save the schematic diagram with its current name. The default name is " EXAMPLE.SCH ".
In the case of "Save As…", a new window appears, into which you are to enter the design name. Use the keyboard and type the desired file name. Press " Save ". Your design is now registered within the .SCH appendix.
Click on File -> Select Foundry. The list of available processes appears. The initial design rule file is "default.tec". Various technologies are available from 1.2 µm downto 32-nm. Click on the rule file name and the software reconfigures itself in order to adapt to the new process.
Note that a set of applications was been released for nano-scale technologies, starting 90-nm CMOS technology. These application notes describe the context, trends, MOS performances as well as the implementation in Microwind and Dsch.
Lithography
Year
Metal layers
Core supply (V)
Core Oxide (nm)
Chip size (mm)
Input/output pads
Dsch rule file
1.2µm
1986
2
5.0
25
5x5
250
Cmos12.tec
0.7µm
1988
2
5.0
20
7x7
350
Cmos08.tec
0.5µm
1992
3
3.3
12
10x10
600
Cmos06.tec
0.35µm
1994
5
3.3
7
15x15
800
Cmos035.tec
0.25µm
1996
6
2.5
5
17x17
1000
Cmos025.tec
0.18µm
1998
6
1.8
3
20x20
1500
Cmos018.tec
0.12µm
2001
6-8
1.2
2
22x20
1800
Cmos012.tec
90nm
2003
6-10
1.0-1.2
1.2
25x20
2000
65nm
2005
6-12
1.0-1.2
1.2
25x20
3000
45nm 2007 6-12 0.8-1.1 1.2 25x20 4000 Cmos45n.rul 32nm 2010 6-12 0.8-1.1 0.9 25x20 5000 Cmos32n.rul
Select the command Generate Spice to convert the schematic diagram into a SPICE compatible file. Notice that Dsch has been made compatible with WinSpice (See www.winspice.com) a freeware SPICE for PC based on Berkeley Spice. The following window appears. The SPICE text appears on the left side of the screen.
On the right side:
An application note about the interfacing of DSCH 3.5 with WinSpice3 has been released, with details about DC, TRAN, and AC analyses. Click here for more details about this application note.
Select the command Generate Subcircuit to convert the schematic diagram into a new symbol which includes the VERILOG description as a sub-circuit. The following window appears. Click "Verilog" to see the VERILOG description that is included in the symbol.
The list of I/Os appear on the left side of the screen. On the right side,
The conversion of the schematic diagram into a VERILOG description is usefull for compiling the schematic diagram into layout using Microwind. The verilog description is a text with a predefined syntax. Basically, the text includes a description of the module (name, input, output), the internal wires, and the list of primitives. An example of veriolog file generated by DSCH is given below.
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COMMENTS: //
MODULE DECLARATION: "module", name, and list of I/Os.
MODULE CONTENTS: list of inputs, of outputs, of internal wires, and the declaration of primitives, always with the primitive keyword first, the name second, and the list of parameters. For example: NOT is the primitive for the inverter, "inv_7" is the cell name, "in1" is the input and "outInv" the output.
MODULE END: "endmodule".
The command File -> Properties provides some information about the current technology, the percentage of memory used by the schematic diagram and its detailed contents.
In the Technology part, details on the time unit, voltage supply, typical delay and typical wire delay are provided, which configure the delay estimation and current estimation during logic simulation.
Switch to monochrome: the layout is drawn in black and white. This type of drawing is convenient to build monochrome documentation. Press "Alt"+"Print Screen" to copy the screen to the clipboard. Then, open "Word", click "Edit-> Paste". The screen is inserted into the document.
Click on File ->Print Schema to transfer the graphical contents of the screen to the printer. Automatically, DSCH3 is switched to monochrome mode prior to printing. Alternatively, you can make a copy of the window into the clipboard in order to import the screen into your favorite text editor by pressing <Alt>+<Print Screen>. In the text editor or in the graphic editor, simply click on " Edit ->Paste ".
We recommend that you switch to monochrome mode first by invoking the function File -> Monochrom/Color. In that case the layout will be drawn in a white background color using gray levels and patterns.
Click on Leave -> Exit DSCH in the main menu. If you have made a design or if you have modified some data, you will be asked to save it. After confirmation, you can return to Windows.