Lab2: LED Introduction; CMOS Complex Gates

Introduction

The purpose of this lab is to introduce the student to schematic capture using the Mentor/GDT LED editor. LED will also be used later in the semester for CMOS layouts. The student is also to implement a complex gate in CMOS, and simulate it in HSPICE.

Setup

1. Make a directory called 'lab2', and copy all files from ~reese/EE4253/lab2 into it.

Part 1 - Complex Gate Design

The files you copied over are spice AC (cgate_ac.sp) and dc (cgate_dc.sp) analysis files for a complex boolean gate. Both of these files include a file called 'cgate'.sp; this file is to contain the CMOS transistors that define the complex gate.

First, design your complex gate based on the logic equation you were assigned via Lab2 Assignments . Then edit the file 'cgate.sp' and instantiate your complex gate using PMOS/NMOS transistor elements. The parameter 'L_min' should be used as the width for all transistors; 'W_pmos' is the width of all pmos transistors, and 'W_nmos' is the width of all nmos transistors. The input node names are 'A', 'B', 'C', 'D'; the output node name is 'Z'. The global nodes 'vdd' and 'gnd' have been defined.

AC Simulation

Run the hspice 'cgate_ac.sp' simulation and use MWAVES to verify that your gate is working correctly. Produce a plot which has 5 separate panels; panels 1-4 will have the input waveforms for nodes A,B,C,D respective while panel 5 will have the output waveform, node Z. Produce a hardcopy plot of these panels where all panels are plotted on the same page.

To produce multiple panels in MWAVEs, you have to double click on the 'Add Panel' selection in the 'Panel List' scroll window. Then click on a Panel to make it active; any waveforms you select in the 'Results Browser' will be plotted on the active window. Be sure that you change the plot color of the first wave to 'WHITE' so that your curves will be visible on the hardcopy plot.

DC Simulation

Run hspice on 'cgate_dc.sp' for the DC analysis simulation. This will produce measurement files .ms0 thru .ms7, these can be placed in one file by doing:

  cat cgate_dc.mt* > results.dc

Part 2 - Schematic Capture with LED

Do the Led Editor Introduction. Then create an Led schematic which documents your design. All terminals and transistors MUST be labeled with the same names as used in the HSPICE file. You should also add some text documentation to the schematic that has the logic equation you implemented, plus your name, lab section (day and time) and your social security number.

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