Tiny Tapeout GF 26b · Die T26B on wafer.space Run 2
100Mbps Ethernet Accelerator Wrapper
288 · Accelerators · 1 × 2 tiles
by Julia Desmazes · repository @Essenceia
Rendered from the layout at 0.33 µm per pixel. Layers: NwellDiffusionPolysiliconMetal 1Metal 2Metal 3Metal 4Metal 5Top metalPad openings
Logic density
| Core average logic cells per mm² | 21k (27% of buffer maximum) |
|---|---|
| Densest 0.1 mm square logic cells per mm² | 26k (34% of buffer maximum) |
| Core covered by logic | 63% |
| Transistor density transistors per mm² | 286k average, 314k in the 0.1 mm square with the most logic cells |
Every figure here is measured from the public layout, the same way for every design on the chip: see data and method, and how its designs used the process.
Network connected accelerator wrapper, connected to custom bfloat16 multiplier.
Source repository Its page on Tiny TapeoutBuy a chip and board
| Size | 347 × 325 µm (0.113 mm²) |
|---|---|
| Macro | tt_um_teapot |
| Files | documentation · licence · layout and netlist in Tiny Tapeout GF 26b |
| Tiles | 1 × 2 at column 3, row 14 of the tile grid |
| Mux address | 288 |
| Language | Verilog |
| Clock | 50 MHz |
| Built with | LibreLane 3.0.3, open_pdks 54435919abff |
| Transistors | 33,045 |
| Logic cells | 2,406 + 4,078 filler and tap cells |
| Libraries | 7t-5V (2k) |
| SRAM | No SRAM |
Process features
Which parts of the GF180MCU process this design uses: its transistor voltages and where they come from, its gate oxides, and any devices drawn by hand outside the standard cells, SRAM and pads.
| 5 V | 7t-5V standard cells |
|---|---|
| Gate oxides | Thick only (5 V/6 V) in the design itself |
Where the area went
How this project's area splits between logic cells, filler and tap cells and other.
- Logic cells 0.07 mm² (63%)
- Filler and tap cells 0.03 mm² (30%)
- Other 0.01 mm² (7%)
Most used cells
The ten standard cells this design uses most.
| Cell | Library | Instances | What it does |
|---|---|---|---|
| dffq_1 | 7t-5V | 407 | D flip-flop (1 bit storage) |
| nand2_1 | 7t-5V | 293 | 2-input NAND gate |
| clkinv_1 | 7t-5V | 136 | Clock inverter |
| nor2_1 | 7t-5V | 124 | 2-input NOR gate |
| oai21_1 | 7t-5V | 121 | OR-AND-Invert compound gate |
| oai211_1 | 7t-5V | 94 | OR-AND-Invert compound gate |
| aoi22_1 | 7t-5V | 81 | AND-OR-Invert (2x2 inputs) |
| clkbuf_1 | 7t-5V | 80 | Clock buffer |
| dlyb_1 | 7t-5V | 79 | Delay buffer |
| aoi21_1 | 7t-5V | 78 | AND-OR-Invert compound gate |
Logic density map
Logic cells per mm² in each 0.1 mm square of the project (counted in the square, scaled up to a mm²). Hatched outlines are SRAM macros; the red outline is the densest 0.1 mm square that avoids them (26k logic cells per mm²), found by sliding a 0.1 mm square over the project in 20 µm steps, so it can straddle the fixed squares and find more than any one of them. Squares at the edges are partial, so they read low.
How this design grew
Expresso Ethernet switch has been made on 3 shuttles since Jun 2026. Every version, oldest first, with this one in bold:
- Jun 2026 · Tiny Tapeout GF 0.3 Until heat death do us part — 2 × 2 tiles, the heat death of the universe beacon
- Jun 2026 · Tiny Tapeout GF 26b 100Mbps Ethernet Accelerator Wrapper — 1 × 2 tiles 100Mbps 3 port Ethernet switch — 2 × 2 tiles
- Jul 2026 · wafer.space Run 2 CAFE Expresso Ethernet Chip: 100Mbps Ethernet switch + Heat death of the Universe Beacon - 0.5x0.5 version - Preferred version — ½ × ½ slot
Tiny Tapeout tile Google shuttle wafer.space die
From a Tiny Tapeout tile to a whole die
Expresso Ethernet switch started as a few tiles on Tiny Tapeout GF 0.3 and went on to a die of its own on wafer.space Run 2. When your design outgrows its tiles, a whole die on a wafer.space run is the next step.
Tiny Tapeout and wafer.space are independent companies that work together (announcement). Tiny Tapeout runs its own shuttles: it takes the projects, builds the die, and sells and supports the chips and boards. wafer.space has the dies manufactured on its GF180MCU runs, and these pages are wafer.space's measurements of them. For anything about a Tiny Tapeout project, chip or order, contact Tiny Tapeout.