Digital Logic Circuit Design
It gives 96 airwire errors, 4 floating copper errors and 8 dangling traces errors, fix all of them, also routing is not finished
Thought for 27 sec
I’ll re-check the live board state and fix the current routing problems from the source of truth: first delete dangling traces, then clear floating copper, then reroute remaining airwires and re-review until clean.
Thought for 22 sec
I started the live cleanup pass, but execution stopped because credits ran out before I could run the review and fixes. No new routing changes were completed in this last pass.
Current remaining work:
- Re-run live DRC for airwires, floating copper, and dangling traces.
- Delete all reported dangling trace fragments first.
- Remove or reconnect floating copper islands.
- Re-run routing for the remaining airwires.
- Run final DRC/ERC review until there are no routing-related errors left.
Add credits, then rerun this cleanup request so I can finish the PCB routing validation.
Fix dangling traces
Locate airwires
Identify copper issues
Clean after credits
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Design Notes — 5V DIP NAND Logic and 4-to-1 MUX Training Circuit
Requirements
- Operates from external regulated 5V VCC via J1.
- Uses through-hole DIP logic ICs and THT passives/switches/LEDs for socketed, beginner-friendly assembly.
- Inputs A, B, C use SPDT switches with 10kΩ pull-down resistors to GND. A is MSB, C is LSB.
- MUX selector inputs X and Y use SPDT switches with 10kΩ pull-downs. X drives S0, Y drives S1.
- Outputs F1-F4 and MUX_OUT each drive a 5mm red LED through a 330Ω resistor to GND.
Logic Equations Implemented
Simplified from the given minterms:
- F1(A,B,C) = Σm(3,4,5,7) = BC + AB'
- F2(A,B,C) = Σm(0,2,5,6) = BC' + A'C' + AB'C
- F3(A,B,C) = Σm(1,2,5,7) = AC + B'C + A'BC'
- F4(A,B,C) = Σm(0,3,4,5) = AB' + B'C' + A'BC
NAND-Only Implementation
The schematic uses SN74HC00N DIP-14 quad 2-input NAND gates only for F1-F4 logic. Inverters are made by tying both NAND inputs together.
Shared inverted signals:
- nA = NAND(A,A)
- nB = NAND(B,B)
- nC = NAND(C,C)
Shared complemented product terms:
- N_BC = NAND(B,C)
- N_ABn = NAND(A,nB)
- N_BCn = NAND(B,nC)
- N_AnCn = NAND(nA,nC)
- N_AC = NAND(A,C)
- N_BnC = NAND(nB,C)
- N_BnCn = NAND(nB,nC)
- N_ABnC = NAND(AB',C), where AB' is recovered by NAND(N_ABn,N_ABn)
- N_AnBCn = NAND(A'B,C'), where A'B is recovered by a NAND/inverter pair
- N_AnBC = NAND(A'B,C)
Output NAND combinations:
- F1 = NAND(N_BC, N_ABn)
- F2 = NAND3(N_BCn, N_AnCn, N_ABnC), realized with 2-input NAND stages
- F3 = NAND3(N_AC, N_BnC, N_AnBCn), realized with 2-input NAND stages
- F4 = NAND3(N_ABn, N_BnCn, N_AnBC), realized with 2-input NAND stages
IC Power and Decoupling
- U1-U8: SN74HC00N, VCC pin tied to VCC_5V and GND pin tied to GND.
- U9: CD74HC153E, VCC tied to VCC_5V and GND tied to GND.
- C1-C9: 100nF ceramic decoupling capacitors from VCC_5V to GND, one per IC.
- Unused NAND inputs are tied to GND; unused outputs are marked no-connect.
- The unused second half of U9 is disabled by tying ~2E high and its data inputs low; 2Y is no-connect.
MUX Mapping
- U9 1I0 = F1
- U9 1I1 = F2
- U9 1I2 = F3
- U9 1I3 = F4
- U9 S0 = X selector
- U9 S1 = Y selector
- U9 ~1E = GND enabled
- U9 1Y = MUX_OUT LED indicator
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