Older nodes (e.g., 180nm, 130nm) may use SVT (Standard Vt) instead of RVT. 3.4 Physical Variant Modifiers These indicate special layout arrangements.
[Cell Type]_[Drive]_[Vt][Special Modifier][Height/Width Code] Common examples: INVX1LVT → Inverter, drive 1, low Vt. NAND2X2HVT → 2-input NAND, drive 2, high Vt. DFFARX4RVT → D flip-flop with async reset, drive 4, regular Vt. 3.1 Base Function (Cell Type) | Code | Function | |--------|----------------------------------| | INV | Inverter | | NAND2 | 2-input NAND | | NOR2 | 2-input NOR | | AND2 | 2-input AND | | OR2 | 2-input OR | | XOR2 | 2-input XOR | | DFF | D flip-flop (rising edge) | | DFFR | DFF with asynchronous reset | | DFFS | DFF with asynchronous set | | DFFRS | DFF with both reset and set | | DLH | Latch | | AOI21 | AND-OR-invert (2+1 input) | | OAI21 | OR-AND-invert | | BUF | Buffer | | TIEH | Tie-high (VDD) | | TIEL | Tie-low (VSS) | | DELAY | Delay cell | 3.2 Drive Strength (X ) Indicates relative current drive capability (higher number = larger transistors, faster slew, higher leakage, larger area). tsmc standard cell naming convention
| Code | Track height (metal 2 pitch) | |--------|------------------------------| | 6T | 6 tracks | | 7.5T | 7.5 tracks | | 9T | 9 tracks (high performance) | Older nodes (e
| Code | Vt type | Speed | Leakage | |-------|----------------|-------|---------| | LVT | Low Vt | Fast | High | | RVT | Regular Vt | Medium| Medium | | HVT | High Vt | Slow | Low | | ULVT | Ultra-low Vt | Fastest| Highest | | ELVT | Extreme low Vt | (deprecated in some nodes) | | NAND2X2HVT → 2-input NAND, drive 2, high Vt
| Code | Relative drive | |------|----------------| | X0.5 | Ultra-weak | | X1 | Unit drive | | X2 | 2× unit | | X4 | 4× unit | | X8 | 8× unit | | X16 | Max drive |
| Field | Example codes | |--------------|----------------------------------------| | Function | INV, NAND2, DFFR, AOI21 | | Drive | X0.5, X1, X2, X4, X8, X16 | | Vt | LVT, RVT, HVT, ULVT, ELVT | | Physical | _D, _P, _F, _CK, _ISO, _LS | | Track height | 6T, 7.5T, 9T (node dependent) |