PHASER — signal-flow flowchart
PHASER — signal-flow flowchart
Image rep algo 5 · slots 5 · unit 0 (I-RAM load 84) · family modulation · confidence medium.
phaser: LFO-swept first-order all-pass chain (~0.438 +/-0.025), 0.3 feedback
106 words, 14 class-A coefficient multiplies (9 named), 0 instructions still opaque, 17 of 106 not yet decoded. Landmarks detected: 2 LFO phase word(s), 2 waveshaper LUT selector(s), 2 all-pass marker(s).
flowchart TD
N0["Stereo input (L / R)"]
N1["LFO phase accumulator<br/>phase += f/44100 (Q0.23), wrap at 0x7FFFFF<br/>+ waveform lookup (LUT)"]
N0 --> N1
N2["controls: DEPTH, LFO SPEED, RESONANCE, MANUAL, PHASE, LFO WAVEFORM"]
N1 -.-> N2
N3["All-pass / phaser chain<br/>2 marker(s); g·d ± feedback (stage count OPEN)"]
N1 --> N3
N4["controls: RESONANCE, MANUAL, PHASE"]
N3 -.-> N4
N5["VOLUME<br/>output level"]
N3 --> N5
N6["REV SEND<br/>to reverb bus"]
N5 --> N6
N7["Output (RETURN to kernel epilogue)"]
N6 --> N7
classDef io fill:#e8eef7,stroke:#33475b,stroke-width:1px,color:#111;
classDef proven fill:#d7f0d7,stroke:#2e7d32,stroke-width:2px,color:#111;
classDef measured fill:#dbe9fb,stroke:#1565c0,stroke-width:1.5px,color:#111;
classDef inferred fill:#fdf0d5,stroke:#b8860b,stroke-width:1.5px,color:#111;
classDef open fill:#eeeeee,stroke:#888,stroke-width:1px,color:#333,stroke-dasharray:5 5;
classDef ctrl fill:#f3e8fb,stroke:#6a1b9a,stroke-width:1px,color:#111;
class N0,N7 io;
class N1 measured;
class N2,N4,N5,N6 ctrl;
class N3 inferred;
Classic-topology match
Most likely textbook topology: LFO-modulated delay (chorus/flanger/ensemble) or swept all-pass chain (phaser).
An LFO phase accumulator (a D-RAM cell ramping by the LFO-SPEED each frame) modulates a short delay tap (chorus/flanger, + feedback/resonance) or sweeps an all-pass chain (phaser sweeps notches, ~0 delay-DRAM but many z⁻¹ pairs).
Instruction hint: the LFO cell’s per-frame increment IS the LFO-SPEED parameter (LIVE: CHORUS cell 0x10 ramps +114/frame, →+494 when the SPEED knob is driven); the LFO-conditional MACs are the class-A words that do NOT fire every frame (LIVE: FLANGER’s SRC 0x08 coef-square, f31=4).
UI parameters (MEASURED, notes/kn5000-dsp-paramlist.md): DEPTH, LFO SPEED, RESONANCE, MANUAL, PHASE, LFO WAVEFORM, VOLUME, REV SEND.
Per-instruction detail: ../disasm/prog05_phaser.dsm. Confidence legend and method: README.md. Narrative: the MAME development blog, KN5000 effects-DSP series (Parts 78-84). Reference: the project docs site, /effects-dsp/.