id: rylr998_phy_decode
label: RYLR998 PHY Decoder
category: '[RYLR998]/PHY'
flags: [python, cpp]

documentation: |-
  LoRa PHY layer decoder.

  Complete receive chain: Gray decode → Deinterleave → Hamming FEC → Dewhiten

  Decodes CSS-demodulated symbol bins into payload bytes using the
  gr-lora_sdr compatible signal chain.

  RX chain order:
    1. Apply correction: (bin - cfo_bin - 1) % N
    2. Reduced rate (header): divide by 4, use SF-2 bits
    3. Gray map: x ^ (x >> 1) (counterintuitive but correct!)
    4. Deinterleave
    5. Hamming FEC decode
    6. Dewhiten payload
    7. CRC check

  Input: Aligned data symbol bins (from Frame Sync)
  Output: Decoded payload bytes

templates:
  imports: from rylr998 import phy_decode
  make: rylr998.phy_decode(sf=${sf}, cr=${cr}, has_crc=${has_crc}, ldro=${ldro}, implicit_header=${implicit_header}, payload_len=${payload_len})

parameters:
  - id: sf
    label: Spreading Factor
    dtype: int
    default: 9
    options: [7, 8, 9, 10, 11, 12]
    option_labels: ['SF7', 'SF8', 'SF9', 'SF10', 'SF11', 'SF12']

  - id: cr
    label: Coding Rate
    dtype: int
    default: 1
    options: [1, 2, 3, 4]
    option_labels: ['4/5', '4/6', '4/7', '4/8']

  - id: has_crc
    label: CRC Enabled
    dtype: bool
    default: 'True'
    options: ['True', 'False']

  - id: ldro
    label: Low Data Rate Opt
    dtype: bool
    default: 'False'
    options: ['True', 'False']

  - id: implicit_header
    label: Implicit Header
    dtype: bool
    default: 'False'
    options: ['True', 'False']

  - id: payload_len
    label: Payload Length (Implicit)
    dtype: int
    default: 0
    hide: ${ 'all' if not implicit_header else 'none' }

inputs:
  - label: symbols
    domain: message
    dtype: int

outputs:
  - label: payload
    domain: message
    dtype: byte

  - label: frame_info
    domain: message
    optional: true

file_format: 1