Tiny Tapeout > Tiny Tapeout Chips > Tiny Tapeout SKY 26b > 837 IEEE Rule 30 Cellular Automaton VGA Display
837 IEEE Rule 30 Cellular Automaton VGA Display
837 : IEEE Rule 30 Cellular Automaton VGA Display
- Author: NAVEEN KUMAAR S
- Description: Hardware implementation of Wolfram Rule 30 cellular automaton rendered on a VGA monitor.
- GitHub repository
- Open in 3D viewer
- Open in VGA Playground
- Clock: 25000000 Hz
How it works
Rule 30 is a 1D cellular automaton discovered by Stephen Wolfram in 1983.
Despite having only one simple rule — new_cell = left XOR (centre OR right) —
it produces behaviour so chaotic it was used as Mathematica's built-in
random number generator for many years.
This design implements Rule 30 directly in silicon:
- A 320-bit register stores the current generation
- Every row of pixels, all 320 cells update simultaneously in parallel
- Each frame starts from a single seed cell at position 160 (centre)
- 480 rows = 480 generations of chaotic evolution displayed top to bottom
- Each cell maps to 2 horizontal pixels (320 cells × 2 = 640px wide)
The result is the famous asymmetric triangular chaos pattern that expands from the centre of the screen downward.
Colour palettes (ui_in[1:0]):
00= Green on black (classic terminal)01= Fire (yellow → orange → red with depth)10= Cyan / Blue11= Rainbow (colour changes with row depth)
How to test
- Connect a VGA monitor via the Tiny VGA Pmod (connect to uo_out pins)
- Set clock to 25 MHz
- Assert and release reset (rst_n)
- You should see a triangle of chaos expanding from centre-top of screen
- Toggle ui_in[0] and ui_in[1] to cycle through colour palettes
Expected output: A triangular pattern of black and coloured pixels expanding from a single point at the top centre, filling the entire screen with chaotic but deterministic cellular automaton evolution.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | Palette bit 0 | VGA Red MSB | |
| 1 | Palette bit 1 | VGA Green MSB | |
| 2 | VGA Blue MSB | ||
| 3 | VGA Vsync | ||
| 4 | VGA Red LSB | ||
| 5 | VGA Green LSB | ||
| 6 | VGA Blue LSB | ||
| 7 | VGA Hsync |