SR NAND Latch: Active-Low Input Construction
Standard IC datasheets almost exclusively use active-low control signals for set and reset functions due to the inherent speed and area advantages of NAND logic. The cross-coupled NAND structure forms the foundational memory element for these systems.
The circuit must store a single bit of state, Q, and its complement, Q_bar. The inputs are active-low: driving S_bar low sets the state to 1, while driving R_bar low resets the state to 0. Driving both inputs low simultaneously forces both outputs high.
| S_bar | R_bar | Q | Q_bar | |---------|---------|-----|---------| | 0 | 0 | 1 | 1 | | 0 | 1 | 1 | 0 | | 1 | 0 | 0 | 1 | | 1 | 1 | Q | Q_bar |
Constraints
- Use exactly two 2-input NAND gates.
- Name the inputs exactly
S_barandR_bar. - Name the outputs exactly
QandQ_bar. - Do not use pre-built latch or flip-flop primitives.
Topics
Solve this problem
Place the gates, wire them up and watch the signals settle. Every submission runs on the same simulation engine that grades it.
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