wafer.space Run 2

16-bit RISC CPU

AS16 · RISC-V and CPUs · 1 × ½ slot

Rendered from the layout at 2.5 µm per pixel. Layers: NwellDiffusionPolysiliconMetal 1Metal 2Metal 3Metal 4Metal 5Top metalPad openings

Logic density

Inside the core
logic cells per mm²
1k (1% of buffer maximum)
over the 5.02 mm² core: what the design itself packed
Inside the seal ring
logic cells per mm²
1k
over all 9.61 mm² of the slot, pad ring included
Densest mm²
logic cells per mm²
5k (7% of buffer maximum)
Core covered by logic4%
Transistor density
transistors per mm²
224k average, 212k in the mm² with the most logic cells

Every figure here is measured from the public layout, the same way for every design on the run: see data and method, and how its designs used the process.

A 16-bit RISC CPU designed by Adnan Saad.

Die3.93 × 2.53 mm (9.9 mm²)
Core area5.02 mm² inside the pad ring
as set in the design's own layout settings
Inside the seal ring9.61 mm² (the die less its 26 µm seal ring)
Placements1 on the reticle, in slot A2 AS16 on the reticle
Bond pads72
Transistors1,123,551
Logic cells5,508 + 92,536 filler and tap cells
Libraries 7t-5V (6k)
SRAM2 macros, 8,192 bits

Submission

LicenceApache-2.0 declared
Repository: Apache-2.0 in LICENSE — agrees
Templatewafer-space/gf180mcu-project-template 1.5.7
How it was checked
Commit and PDK pin The licence and template were read from the repository at commit 0cfc5a56b99a.The template release named above is the one whose Makefile pins the same PDK as that commit (PDK_COMMIT d658698bd8bc).
Chip-on-boardNot selected at submission
The check it was accepted on ran with chip-on-board selected; it was switched off afterwards.
PrecheckPassed the check it was accepted on, 2026-07-13, gf180mcu-precheck 1.7.1 (from its image)
Passed latest re-run, 2026-07-14, gf180mcu-precheck 1.7.2 (from its image)
step results and logs

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 V7t-5V standard cells, fd SRAM
Gate oxidesThick only (5 V/6 V) in the design itself
I/O librarygf180mcu_fd_io (758 cells)

Where the area went

How this design's area splits between logic cells, SRAM, filler and tap cells, other and pad ring.

44%
50%
  • Logic cells 0.19 mm² (2%)
  • SRAM 0.42 mm² (4%)
  • Filler and tap cells 4.36 mm² (44%)
  • Other 0.05 mm² (1%)
  • Pad ring 4.92 mm² (50%)

Most used cells

The ten standard cells this design uses most.

CellLibraryInstancesWhat it does
dlyb_17t-5V 3,585Delay buffer
nand2_17t-5V 4212-input NAND gate
dffrnq_17t-5V 329D flip-flop with reset
oai21_17t-5V 320OR-AND-Invert compound gate
dlyc_17t-5V 74Delay buffer
buf_47t-5V 61Buffer (4x drive)
nor2_17t-5V 612-input NOR gate
mux4_17t-5V 564-input multiplexer
aoi22_17t-5V 54AND-OR-Invert (2x2 inputs)
nand3_17t-5V 493-input NAND gate

Logic density map

9 logic cells, 50,481 transistors, 22% SRAM 843 logic cells, 114,194 transistors, 20% SRAM 4,626 logic cells, 144,736 transistors 9 logic cells, 64,278 transistors 0 logic cells, 125,622 transistors 0 logic cells, 221,340 transistors 9 logic cells, 221,462 transistors 9 logic cells, 111,666 transistors 0 logic cells, 13,414 transistors 0 logic cells, 22,193 transistors 0 logic cells, 22,225 transistors 3 logic cells, 11,940 transistors gf180mcu_fd_ip_sram__sram512x8m8wm1 gf180mcu_fd_ip_sram__sram512x8m8wm1 Densest SRAM-free mm²: 5,430 logic cells <1k 1k 5k <1k 0 0 <1k <1k

Logic cells per mm² in each square millimetre of the die. Hatched outlines are SRAM macros; the red outline is the densest mm² that avoids them (5k logic cells per mm²), found by sliding a 1 mm square over the die in 0.1 mm 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.

SRAM macros

The ready-made memory blocks this design uses.

MacroCountBits each
gf180mcu_fd_ip_sram__sram512x8m8wm12 4,096

Precheck

Before a design is made, the wafer.space platform checks it against the foundry's design rules. AS16 was accepted on this check, and has been checked again since with newer rules.

All 17 steps passed, with 0 KLayout DRC errors, on 2026-07-13.

Every step, and the latest re-run
StepAccepted on
check 472, 2026-07-13, initial, gf180mcu-precheck 1.7.1 (from its image)
PDK open_pdks 1.0.604, LibreLane 5fe3db1
Latest re-run
check 533, 2026-07-14, drc_update, gf180mcu-precheck 1.7.2 (from its image)
PDK open_pdks 1.0.604, LibreLane 5fe3db1
KLayout.ReadLayoutpassedpassed
KLayout.CheckTopLevelpassedpassed
KLayout.CheckSizepassedpassed
KLayout.CheckPadMaskpassednot in this flow
KLayout.GenerateIDpassedpassed
KLayout.Renderpassedpassed
KLayout.Densitypassedpassed
Checker.KLayoutDensitypassedpassed
KLayout.ZeroAreaPolygonspassedpassed
Checker.KLayoutZeroAreaPolygonspassedpassed
KLayout.Antennapassedpassed
Checker.KLayoutAntennapassedpassed
Magic.DRCpassedpassed
Checker.MagicDRCpassedpassed
KLayout.DRCpassedpassed
Checker.KLayoutDRCpassedpassed
KLayout.WriteLayoutpassedpassed
KLayout DRC errors00
Magic DRC errors (advisory)00
Filessteps · log (gzip)steps · log (gzip)

The steps of the gf180mcu-precheck LibreLane flow, as run by platform.wafer.space. The design was accepted on the newest finished check before it was submitted; later re-runs check the same file with updated rules. KLayout DRC is the sign-off check. Magic DRC is advisory: its count does not stop a design. In the logs, Magic's "Error while reading cell" lines about fill cells are messages from its reader, not check failures.

Want a chip of your own like this one?

wafer.space Run 3 takes orders until 9 December 2026. Or start smaller with Tiny Tapeout: the next Tiny Tapeout GF180MCU chips take projects until 7 December 2026, for wafer.space Run 3.