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Introduction

Blue noise rises at +3 dB per octave: power concentrated at high frequencies, the preferred dither/error-diffusion spectrum. It is built as $b[n] = p[n] - p[n-1]$ where $p$ is an internal Voss-McCartney pink total: the first difference contributes $+6$ dB/oct, on top of pink’s $-3$, giving $+3$ dB/oct over the covered octaves.

Blue noise PSD

Measured on the bit-exact model the hardware is verified against; the dashed line is the ideal +3 dB/octave slope.

Pin Description

CE Input 1 bit BIT
Clock enable: one new sample per clock where high. Default: ‘1’.
Default: 1
CLK Input 1 bit BIT
Clock.
Default: Default Board Clock
RESET Input 1 bit BIT
Clears the internal state and restarts from the seed.
Default: Default Board Reset
OUT Output 16 bit BIT VECTOR
Blue noise sample, signed, OutputBits wide, saturated.
DV_OUT Output 1 bit BIT
High on every clock carrying a new sample.

Properties

Property window

Output bits OutputBits

Width of the OUT word (2..32), signed.

Output width (2..32), signed, saturated.

Default: 16

Range: 2 – 32

Octaves Octaves

Octave registers of the internal pink source: the +3 dB/oct slope holds from fs/2 down to fs/2^Octaves.

Octave registers of the internal pink source (4..24): +3 dB/oct holds from fs/2 down to fs/2^Octaves.

Default: 16

Range: 4 – 24

SEED (32 digit hex) SEED

Seed of the embedded white generator (128 bit hex), expanded internally with SplitMix64. Auto-randomized when the component is created, so multiple instances produce independent noise; editable for reproducible runs. RESET restarts the sequence. Blue noise, +3 dB/octave (first difference of an internal pink source).

128-bit seed of the embedded white generator, 32 hexadecimal digits (auto-randomized at placement, editable for reproducible runs). Every string of exactly 32 hex digits is a valid seed - repeated digits, all zeros and two identical 64-bit halves included; a wrong length or a non-hex digit is a compile error. Two seeds that differ at all give two independent noise streams (guaranteed when they differ in one 64-bit half, which includes any single-digit difference), which is what makes several instances of this block decorrelated. NOTE: the seed expansion was corrected in this version, so the same seed produces a different (equally reproducible) stream than in earlier releases.

Default: 7E44C6B59C2D462ABB6ED49775F6DD06

Usage

Output normalized (shift) and saturated to OutputBits; one sample per CE clock, one clock latency. CE defaults to ‘1’.