DIP switch
A bank of independent toggle switches in a single package. Each position has its own output pin and its own state, and you flip one by clicking it. It is the tidy way to feed a circuit several fixed inputs at once — the kind of settings you set before running and rarely touch again.
Four switches, four outputs
Drop a DIP switch on the canvas and wire each of its output pins to its own LED. Click any position and only that LED changes — the positions are genuinely independent, not a single number split across pins. This is the difference between a DIP switch and a multi-bit input: here each line stands alone.
Setting an address
Feed the switch outputs into a Merger to compose them into one bus, then use that bus as the address lines of a ROM. Now the switch positions select which stored word appears at the output — read the binary straight off the switches. This mirrors how real boards used DIP switches to set a device address before software configuration was common.
Test vectors by hand
When you are checking a combinational block against its truth table, a DIP switch is the fastest input stage: one position per variable, all of them visible at a glance, and no wiring changes between test cases. Walk the switches through the input combinations in order and compare the outputs against the table row by row. For a design with more inputs than the switch has positions, raise its bit width rather than placing a second one, so the whole vector stays in one place.
Citations
- Horowitz, P., & Hill, W. (2015). The art of electronics (3rd ed.). Cambridge University Press. Reference 1
- Mano, M. M., & Ciletti, M. D. (2018). Digital design: With an introduction to the Verilog HDL, VHDL, and SystemVerilog (6th ed.). Pearson. Reference 2