Lab 7 Using Buses in ElectricVLSI

Jesse Duran
Spring 2021
ENGR 338

Introduction:

In this lab we are tasked with designing a ring oscillator and multi bit OR, NOR, NAND, and AND gates using buses

Task 1


Figure1. Ring Oscillator schmematic


Figure2. Ring Oscillator Simulation


Figure3. Ring oscillator bus layout


Figure 4. Ring oscillator Bus simulation.


Figure 7. Ring Oscillator Bus layout clean

Task 2


Figure 8. AND gate schematic clean

Figure 9. 8-bit AND schematic and icon. DRC clean

Figure10. 8-bit AND simulation. input A =11111111, B = 10101010, AandB = 10101010

Figure 11. 8-bit and simulation. input A = 00000000, B = 10101010, output: AandB = 00000000


Figure 12. AND layout DRC and NCC clean


Figure13. 8-bit AND gate DRC and NCC clean

Task 3


Figure14. OR schematic and icon DRC clean


Figure 15. OR simulation. Logic verified


Figure 16. OR layout DRC and NCC clean


Figure 17. OR 8bit schematic and icon


Figure 18. OR 8bit simulation. A=00000000, B=10101010. AorB = 10101010


Figure 19. OR 8bit layout DRC and NCC clean

Task 4


Figure 20. NAND 8bit schematic DRC clean


Figure 21. NAND 8bit simulation. A = 11111111, B= 10101010, AnandB = 01010101

Figure 22. NAND 8bit layout DRC and NCC clean

Task 5



Figure 23. NOR 8bit schematic and layout DRC clean


Figure 24. NOR 8bit simulation A = 00000000, B= 10101010, AorB = 01010101


Figure 25 . NOR 8bit layout DRC and NCC clean

Discussion


This taught us more about using single bit components in order to build mulitbit ones. The concept of buses was introduced in the schematic level. Buses are not availible in the layout view since the it serves as a simplification mechanism. In the layout view, everything is defined on the bottom level, so we must define the connection ourselves. This is similar to how we can make the 100:50 inverter simply in the schmeatic then fully defined in the layout. We also learned about the array function which helps in working fast. The ring oscillator was good for explaining how the buses work and interesting to simulate. After the layer lectures using different metals made more sense.