38 MAW Bird Shooter VGA Game :: Quicker, easier and cheaper to make your own chip!

How it works

MAW Bird Shooter is a fully synthesized single-player arcade game fabricated as a Tiny Tapeout ASIC. It drives a 640×480 60 Hz VGA display directly from the chip's output pins using a 50 MHz system clock.

Game loop

The screen shows an animated bird wandering across the display and a player-controlled crosshair. The player has 10 shots to aim and fire. Each shot is immediately scored as a HIT (crosshair overlaps the bird bounding box) or MISS. After each shot, a brief HIT or MISS overlay is shown before the next round begins. The bird respawns at a pseudo-random position after every shot. Win condition: 7 or more hits out of 10 (≥ 70%). Press SHOOT on the win or lose screen to restart.

Architecture

game_state_fsm — central FSM controlling game flow: RESET → START_SCREEN → SHOOTING → HIT / HIT_DELAY → MISS / MISS_DELAY → WON / LOST.
crosshair_control — moves the crosshair one step per game tick while a directional button is held.
enemy_movement — animates the bird along a triangle-wave trajectory seeded by two independent 16-bit LFSRs, giving varied spawn positions and movement paths.
bird_animated — cycles through five bird sprite frames to produce a flapping wing animation.
render_engine + vgatiming — composites all sprites (bird, crosshair, HIT/MISS/WON/LOST overlays, shot-counter UI) and outputs standard VGA sync signals with 1-bit-per-channel RGB colour.
Game tick — a divide-by-two counter on the 60 Hz VGA frame signal produces a 30 Hz game tick. All movement, FSM transitions, and animations advance only on the game tick, keeping gameplay speed consistent and hardware-rate-independent.
Button conditioning — every button input passes through a two-stage synchroniser (CDC) followed by a dual-edge detector. The held (level) signal drives crosshair movement; the rising edge fires a shot; the falling edge triggers game-state transitions (start/restart), preventing an accidental shot at game start.

How to test

Connect the five button inputs (ui[3..7]) to momentary push-buttons. Each button pin must have a 10 kΩ pull-down resistor to GND so the idle state is logic 0 (see pinout and button wiring note below).
Connect the VGA output pins (uo[3..7]) to a VGA monitor or a TinyVGA PMOD board. The pin order matches the standard Tiny Tapeout VGA PMOD pinout: {HSYNC, VSYNC, R, G, B, GND, GND, GND} on uo[7:0].
Apply a 50 MHz clock and release reset (rst_n = 1).
The start screen appears. Press SHOOT (ui[3]) to begin.
Use UP / DOWN / LEFT / RIGHT (ui[7..4]) to aim the crosshair at the bird, then press SHOOT to fire.
After 10 shots the WON or LOST screen is displayed. Press SHOOT to restart.

External hardware

VGA monitor or TinyVGA PMOD (compatible with Tiny Tapeout VGA PMOD pinout)
5× momentary push-buttons
5× 10 kΩ resistors used as external pull-downs on each button pin (ui[3..7])

Button wiring note: All button inputs are active-high — a logic 1 means the button is pressed. The ASIC has no internal pull resistors on these pins, so each must be held at logic 0 via a 10 kΩ pull-down resistor to GND when idle, and driven to VCC when pressed. Do not use pull-up resistors, as that would invert the polarity and the buttons will not work correctly.

#	Input	Output
0
1
2
3	BTN_SHOOT (active-high, pull-down externally)	VGA_B (Blue, 1-bit)
4	BTN_RIGHT (active-high, pull-down externally)	VGA_G (Green, 1-bit)
5	BTN_LEFT (active-high, pull-down externally)	VGA_R (Red, 1-bit)
6	BTN_DOWN (active-high, pull-down externally)	VGA_VSYNC
7	BTN_UP (active-high, pull-down externally)	VGA_HSYNC

38 MAW Bird Shooter VGA Game