UDP Protocol

Cascading Decima-8 machines

📦 Packet Format

packet_v1 — fixed binary format

Characteristic	Value
Size	37 bytes
Endianness	Little-endian
Purpose	Machine cascading (IN/OUT)

🗂️ Packet Structure

Offset	Field	Type	Description
0	magic	u32	'D8UP' (0x50553844)
4	version	u16	1
6	flags	u16	has_winner, has_bus, has_cycle, has_flags
8	frame_tag	u32	Frame tag
12	domain_id	u8	Domain ID
13	pattern_id	u16	Pattern ID
15	reset_mask16	u16	Reset mask
17	collision_mask16	u16	Collision mask
19	winner_tile_id	u16	Winner ID
21	cycle_time_us	u32	Cycle time
25	flags32_last	u32	Last cycle FLAGS
29	bus16[8]	u8×8	Bus values

🚩 Flags (u16)

Bit	Flag	Description
bit0	has_winner	winner_tile_id/pattern_id valid
bit1	has_bus	bus16[8] valid
bit2	has_cycle	cycle_time_us valid
bit3	has_flags	flags32_last valid

📋 Packet Fields

magic (u32)

'D8UP' (0x50553844)

version (u16)

flags (u16)

bit0: has_winner
bit1: has_bus
bit2: has_cycle
bit3: has_flags

frame_tag (u32)

Unique frame tag for synchronization

domain_id (u8)

Domain ID (0..15)

pattern_id (u16)

Pattern ID (0..32767)
Valid if flags.has_winner

reset_mask16 (u16)

Domain mask for RESET_DOMAIN
Each bit corresponds to a domain

collision_mask16 (u16)

Mask of domains with collision (cnt≥2)
Valid if flags.has_winner

winner_tile_id (u16)

Winner tile ID
Valid if flags.has_winner

cycle_time_us (u32)

Cycle time in microseconds
Valid if flags.has_cycle

flags32_last (u32)

Last cycle FLAGS32:
bit0: READY_LAST
bit1: OVF_ANY_LAST
bit2: COLLIDE_ANY_LAST
Valid if flags.has_flags

bus16[8] (u8×8)

BUS16[0..7] values
Valid if flags.has_bus

🔄 Packet Example

Hex Dump

0000: 44 38 55 50 01 00 0F 00  00 00 00 01 00 00 00 00   D8UP............
0010: 00 01 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0020: 00 00 00 00 00 00 00 00  00 00 00 00               ............

Decode

magic: 'D8UP'
version: 1
flags: 0x000F (has_winner|has_bus|has_cycle|has_flags)
frame_tag: 1
domain_id: 0
pattern_id: 0
reset_mask16: 0
collision_mask16: 0
winner_tile_id: 0
cycle_time_us: 0
flags32_last: 0
bus16: [0, 0, 0, 0, 0, 0, 0, 0]

💻 Usage

Send Packet

import socket

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

packet = struct.pack('<4sHHIIBHHHHIIBBBBBBBB',
    b'D8UP',           # magic
    1,                 # version
    0x000F,            # flags (all fields valid)
    frame_tag,
    domain_id,
    pattern_id,
    reset_mask16,
    collision_mask16,
    winner_tile_id,
    cycle_time_us,
    flags32_last,
    *bus16             # 8 bytes
)

sock.sendto(packet, ('127.0.0.1', 9999))

Receive Packet

data, addr = sock.recvfrom(37)

magic, version, flags, frame_tag, domain_id, pattern_id, \
reset_mask16, collision_mask16, winner_tile_id, cycle_time_us, \
flags32_last, *bus16_bytes = struct.unpack('<4sHHIIBHHHHIIBBBBBBBB', data)

bus16 = list(bus16_bytes)

has_winner = bool(flags & 0x0001)
has_bus = bool(flags & 0x0002)
has_cycle = bool(flags & 0x0004)
has_flags = bool(flags & 0x0008)

🔗 Integration

Input Stream (IN)

Decima-8 receives packets:
- reset_mask16 → EV_RESET_DOMAIN
- pattern_id → target pattern
- bus16 → input data (if has_bus)

Output Stream (OUT)

Decima-8 sends packets:
- frame_tag → synchronization
- winner_tile_id → recognized pattern
- bus16 → bus state
- flags32_last → cycle flags

Bake the Future. Build the Substrate. 🛠️⚡️