Takahe

Universal hardware synthesis tool supporting binary, ternary, stochastic, quantum, duodecimal, nucleotide, epistemic, cellular automata, affective, I Ching, chromatic music theory, particle physics, and Arrow's impossibility theorem.

Named after the takahē (Porphyrio hochstetteri), declared extinct in 1898 and rediscovered alive in the Murchison Mountains in 1948.

What It Does

Takes SystemVerilog and VHDL source and produces gate-level netlists mapped to real foundry cells:

# Binary synthesis to SKY130 130nm
./takahe --lib sky130.lib --map counter.v design.sv

# Ternary synthesis (balanced ternary, à la Setun)
./takahe --radix 3 --opt --parse design.sv

# Duodecimal synthesis (Mesopotamian base-12)
./takahe --radix 12 --opt --parse design.sv

PicoRV32 (a complete RISC-V CPU core) synthesises to 3,305 SKY130 gate instances. Zero parse errors. Zero multi-driver nets.

The Cell Definition Architecture

Every computing paradigm is a .def file containing truth tables. The engine doesn't know what a NAND gate is; it reads the truth table and evaluates it. When you want a new paradigm you write a text file, not C code.

# Binary AND
cell AND radix 2 inputs 2 outputs 1
  truth 0 0 -> 0
  truth 0 1 -> 0
  truth 1 0 -> 0
  truth 1 1 -> 1
end

# Ternary AND (min) — balanced ternary {-1, 0, +1}
cell AND radix 3 inputs 2 outputs 1
  truth -1  0 -> -1
  truth  0  1 ->  0
  truth  1  1 ->  1
  ...
end

The optimiser is radix-aware. Ternary constant propagation, identity detection, and dead cell elimination all work through truth table evaluation rather than hardcoded rules for any particular paradigm.

Thirteen Paradigms

File	Paradigm	Radix	Origin
cells.def	Binary	2	Shannon, 1938
cells_ter.def	Balanced ternary	3	Brusentsov, 1958
cells_stoch.def	Stochastic	2*	Gaines, 1969
cells_qc.def	Quantum (Clifford)	2	Feynman, 1982
cells_doz.def	Duodecimal	12	Sumer, 3000 BCE
cells_dna.def	Nucleotide	4	LUCA, 3.7 Gya
cells_epist.def	Epistemic	7	Inspired by Bochvar, 1938
cells_life.def	Cellular automata	2	Conway/Wolfram
cells_affect.def	Affective	8	Plutchik, 1980
cells_iching.def	I Ching trigrams	8	伏羲, ~3000 BCE
cells_music.def	Music theory	12	Pythagoras/Bach
cells_quark.def	Particle physics	6	Gell-Mann, 1964
cells_arrow.def	Impossibility	6	Arrow, 1951

* Stochastic cells use binary hardware with probabilistic semantics: AND = multiplication, MUX = weighted addition.

Highlights

Ternary: Negation is free because you just flip every trit, no two's complement needed. The 3-way MUX selects from three inputs with one control signal. Brusentsov proved this was better in 1958 and the Soviet Union cancelled it anyway.

Quantum: CNOT, Toffoli, Fredkin, Hadamard, the full Clifford gate set. The classical control plane for a quantum processor synthesises alongside the binary logic so one tool handles both domains.

DNA: Watson-Crick complement serves as the NOT gate, the CODON cell maps three nucleotides to an amino acid index, and the MATCH cell detects base pairing. Your body runs 37 trillion instances of this cell library.

Epistemic: Seven values inspired by Bochvar's original three-valued logic (true, false, indeterminate), extended to include justified true, believed true, and defeated true. The CONSENSUS gate merges knowledge from multiple sources while the DEFEAT gate revokes warrants when counter-evidence arrives. The extension beyond Bochvar's original three values is original work.

Duodecimal: The Mesopotamians counted in base-12 five thousand years ago and we still use their system for hours, months, and music. The half-adder correctly computes 7 sheep + 8 sheep = 3 sheep carry 1 dozen.

Arrow's impossibility: A .def file that documents its own impossibility. The FAIR voting cell is commented out because Arrow proved in 1951 that no truth table satisfying all three fairness axioms can exist, and the file contains the proof.

I Ching: Closes the historical loop. Leibniz saw the trigrams in 1703 and recognised binary arithmetic, Shannon formalised it in 1938, and Takahe generalised beyond it in 2026. The I Ching was a truth table lookup three millennia before anyone called it that.

Four PDK Targets

PDK	Node	Status
SKY130	130nm	Fully supported, five processors synthesised through OpenROAD
IHP SG13G2	130nm BiCMOS	Supported
GF180MCU	180nm	Supported
ASAP7	7nm (predictive)	Supported

FPGA Targeting

Takahe also targets FPGAs via nextpnr JSON output:

./takahe --opt --fpga output.json design.sv
# Then: nextpnr-ice40 --json output.json --pcf pins.pcf --asc out.asc

Currently targets Lattice iCE40 (4-LUT architecture).

Radiation Hardening

Takahe can automatically harden designs for space, nuclear, and defence applications using Triple Modular Redundancy:

# Triplicate all flip-flops, insert majority voters
./takahe --tmr --opt --parse design.sv

# Full TMR (triplicate everything including combinational logic)
./takahe --tmr-full --opt --parse design.sv

Every DFF is tripled. A majority voter (a & b) | (b & c) | (a & c) masks single-event upsets. The voter decomposes to standard AND/OR gates so it works with all backends, all PDKs, and FPGA targeting without any special handling.

Tested Designs

All synthesise with zero parse errors and zero multi-driver nets:

Design	Type	Cells	Source
PicoRV32	RISC-V CPU	3,305	cliffordwolf/picorv32
Voyager FDS	Flight computer	210	designs/voyager_fds.sv
Minuteman D17B	Guidance computer	231	designs/minuteman_d17b.sv
Dozenal ALU	Base-12 arithmetic	41	designs/dozenal_alu.sv
Ruru	Probabilistic processor	157	designs/ruru.sv
qsim	Quantum gate simulator	59	designs/qsim.sv
Setun-70	Ternary processor	153	designs/setun70.sv
VHDL ALU	8-bit ALU (VHDL)	107	designs/vhdl_alu.vhd

Pipeline

SystemVerilog ─┐
               ├→ lex → parse → elaborate → lower → optimise → bit-blast → map → emit
VHDL ──────────┘   ↑                                    ↑                     ↑
              sv_tok.def                           cells_*.def            *.lib
              vhdl_tok.def

Building

make            # build takahe
make test       # run tests (70 tests, zero failures)
make clean      # clean

Requires GCC and nothing else. Zero dependencies beyond libc. C99.

CLI

takahe [flags] <source.sv|.vhd>

  --vhdl          VHDL mode (IEEE 1076-2008)
  --lex           dump tokens
  --parse         dump AST + RTL
  --opt           optimise (cprop + pattern match + DCE)
  --equiv         equivalence check (pre-opt vs post-opt)
  --blif <f>      emit BLIF netlist
  --yosys <f>     emit Yosys JSON netlist
  --lib <f>       Liberty .lib cell library
  --map <f>       emit mapped gate-level Verilog
  --sta <mhz>     static timing analysis at target frequency
  --radix <n>     synthesis radix (2=binary, 3=ternary, 12=dozenal...)
  --lang <en|mi>  message language (en=English, mi=Te Reo Māori)
  --defs <f>      path to sv_tok.def

Full pipeline example

# Synthesise, map to SKY130, run STA at 100MHz
./takahe --lib sky130.lib --map out.v --sta 100 design.sv

# Same thing, but the errors are in Te Reo Māori
./takahe --lib sky130.lib --map out.v --sta 100 --lang mi design.sv

# Ternary synthesis
./takahe --radix 3 --opt --parse design.sv

# Equivalence check: prove optimisation didn't break anything
# ≤24 input bits = exhaustive (formal proof), >24 = random simulation
./takahe --equiv --parse design.sv

ABEND Dumps and Error Codes

When Takahe hits an unrecoverable error it produces a structured ABEND dump in the mainframe tradition, showing exactly what the tool was doing when it failed. The pattern comes from IBM's CICS (1968): if you're going to crash, crash informatively.

╔══════════════════════════════════════╗
║     TAKAHE ABEND — HE HAPA NUKU     ║
╚══════════════════════════════════════╝
  Module:   tk_sta
  Reason:   net pool exhausted during STA forward pass
  Nets:     41 / 100
  Cells:    36 / 100
  Strings:  1 / 1048576 bytes
  Memories: 2

  The takahē was declared extinct in 1898.
  It came back. So can your design.

In Te Reo Māori (--lang mi):

  Wāhanga:   tk_sta
  Take:      kua pau te pūrere whatunga i te wā STA
  ...
  Kia kaha. Ka oti. Ka pai.
  (Be strong. It will be finished. It will be good.)

adding your own language is just adding another .txt file. Theoretically you could have an error dump in ancient sumerian while making a duodecimal chip, how neat!

Error codes

All error messages use structured codes (TK001–TK099) loaded from text files in lang/. To add a new language, create lang/<code>.txt with one message per line.

Range	Category
TK001–009	Lexer and parser errors
TK010–019	Elaboration (parameters, width)
TK020–029	RTL lowering (pool exhaustion, no driver)
TK030–039	Timing (setup/hold violations, combinational loops)
TK040–049	Mapping (bit-blast overflow, Espresso limits)
TK090–099	ABEND dump fields

Transaction journaling

Every optimisation pass is protected by a CICS-style transaction journal. If a pass fails or makes things worse the netlist rolls back to its pre-pass state, no half-optimised netlists ever. The journal records every cell addition, deletion, and modification, and rollback replays the journal in reverse like rewinding a tape except the tape is your netlist.

Project Structure

src/
├── main.c       CLI entry point
├── tk_abend.c   ABEND dumps + bilingual messages
├── tk_jrn.c     CICS-style transaction journal
├── lex/         SV + VHDL lexers, preprocessor, .def loader
├── parse/       SV + VHDL recursive descent parsers
├── elab/        constant eval, elaboration, width inference
├── rtl/         RTL IR + AST-to-RTL lowering
├── opt/         constant propagation, dead cell elimination
├── xform/       bit-blast, pattern matching, Espresso minimiser
├── tech/        Liberty parser, cell defs, PCHIP, STA, timing-driven opt
└── emit/        BLIF, Yosys JSON, gate-level Verilog output

defs/            13 computing paradigm definitions
lang/            bilingual message catalogues (en, mi)
docs/            situation reports, audit logs

Quality Notice

This cell library carries NO WARRANTY regarding copper quality. If your interconnect is of substandard grade you have only yourself to blame for buying from Ea-nasir. You were warned. Nanni was warned. Nobody listens.

Support the Takahē

This tool is named after the takahē, a flightless bird declared extinct in 1898 and rediscovered alive in New Zealand's Murchison Mountains in 1948. The population is still under 500. DOC's Takahē Recovery Programme is the reason the bird exists today.

If this project is useful to you, consider helping keep them alive.

Donate to the Takahē Recovery Programme

License

MPL 2.0. Modify Takahe's files and share your modifications, build around it and your code stays yours. Because chip design shouldn't cost more than a house and alternative computing shouldn't be locked behind anyone's paywall.