558 Choreo8 :: Quicker, easier and cheaper to make your own chip!

Choreo8

An 8-LED visual effects controller with multiple animated patterns, speed control, and pause functionality implemented in Verilog for ASIC fabrication.

What it does

This project creates an engaging LED display controller that generates 8 different animated lighting patterns. From classic Knight Rider effects to random sparkle patterns, it provides a versatile platform for visual displays, status indicators, or decorative lighting applications.

How it works

The LED Pattern Generator operates on a 5MHz system clock and uses a built-in clock divider to create two speed modes:

Fast Mode (speed_sel = 0): Patterns update at 4Hz for dynamic effects
Slow Mode (speed_sel = 1): Patterns update at 1Hz for relaxed viewing

Clock Architecture

The system uses a 5MHz input clock that gets divided internally:

5MHz → 4Hz: Division ratio of 1,250,000 for fast mode
5MHz → 1Hz: Division ratio of 5,000,000 for slow mode

This clock division provides precise timing control for smooth pattern animations while maintaining synchronization across all LED effects.

Core Architecture

Pattern Selection: A 3-bit input (pat_sel) selects from 8 different patterns
Clock Division: Internal divider creates timing references for pattern updates from the 5MHz base clock
Pattern Registers: Each pattern uses dedicated registers to track position and direction
Output Logic: Combinatorial logic generates the 8-bit LED output based on current pattern state

Pattern Descriptions

Pattern	Description	Visual Effect
Knight Rider	Two LEDs start at opposite ends, meet in middle, return	Symmetric converging/diverging LED effect
Walking Pairs	Adjacent LED pair walks left-to-right and back	Bidirectional pair movement with direction reversal
Expand/Contract	LEDs expand from center outward, then contract	Breathing effect from middle
Blink All	All 8 LEDs flash simultaneously	Simple synchronized blinking
Alternate	Checkerboard pattern alternates	10101010 ↔ 01010101 pattern
Marquee	3-LED group rotates around the strip	Theater marquee chasing lights
Random Sparkle	Pseudo-random twinkling using LFSR	Unpredictable sparkle effects
All Off	All LEDs disabled	System standby mode

Key Features

Pause Control: Freeze current pattern state while maintaining position
Enable Control: Module can be disabled while preserving internal state
Asynchronous Reset: Clean initialization of all pattern states
Low Resource Usage: Efficient design suitable for ASIC implementation
Precise Timing: 5MHz base clock ensures accurate pattern timing

How to test

Basic Operation

Power On: Assert rst_n (active low reset) to initialize the system
Enable: Set ena high to activate pattern generation
Pattern Selection: Use pat_sel[2:0] to choose desired pattern (000-111)
Speed Control: Toggle speed_sel for fast (4Hz) or slow (1Hz) operation
Pause: Assert pause to freeze current pattern state

Input Pin Configuration

Input	Pin	Function	Values
`ui_in[2:0]`	Pattern Select	Choose active pattern	000-111
`ui_in[3]`	Speed Select	Control update rate	0=Fast (4Hz), 1=Slow (1Hz)
`ui_in[4]`	Pause	Freeze pattern	0=Run, 1=Pause
`ui_in[5]`	Enable	Module enable/disable	0=Disable, 1=Enable
`ui_in[7:6]`	Unused	Reserved for future use	Don't care

Clock Requirements

Input Clock: 5MHz
Pattern Update Rates:
- Fast mode: 4Hz (250ms per update)
- Slow mode: 1Hz (1000ms per update)

Output Verification

The 8-bit uo_out[7:0] directly drives the LED array. Each bit corresponds to one LED:

uo_out[0] → LED 0 (leftmost)
uo_out[7] → LED 7 (rightmost)

Expected Behavior

Knight Rider: Should see two LEDs moving inward, meeting, then separating
Walking Pairs: Adjacent LED pair should smoothly traverse the strip
Expand/Contract: LEDs should grow from center, then shrink back symmetrically
Random Sparkle: Should display unpredictable but continuous twinkling

#	Input	Output
0	pat_sel[0]	led_out[0]
1	pat_sel[1]	led_out[1]
2	pat_sel[2]	led_out[2]
3	speed_sel	led_out[3]
4	pause	led_out[4]
5	en	led_out[5]
6		led_out[6]
7		led_out[7]

558 Choreo8

558 : Choreo8