NYX1-512

The NYX1-512 chip is a recording peripheral that can implement the Synapse Electrical Broadband node. It supports the following ElectricalBroadbandConfig parameters:

Gain and Filter Parameters

The NYX1-512 chip has tunable filter parameters and gain settings. The value of the low- and high-frequency cutoffs determines the gain of the system. The table below details the valid pairs of filter cutoff values, as well the gain associated with each setting.

Differential Reference Mode

You need to select pairs of electrodes according to the following rules:

1. electrode_id: Select a set of even numbered electrodes which fall between 0–511, inclusive.
2. reference_id: For a given electrode_id n, reference_id = n+1

Global Reference Mode

Alternatively, you can select a global reference according to the following rules:

1. electrode_id: All even OR all odd values between 0–511, inclusive.

2. reference_id: Refer to the following table:

Ground Reference Mode

To use PCB ground as your reference signal:

1. electrode_id: All even OR all odd values between 0–511, inclusive.

2. reference_id: 520

LUX1-16K

The LUX1-16K chip is a stimulation peripheral that can implement the Synapse Optical Stimulation node. It drives an LED array of up to 128 × 128 pixels (16,384 total). It supports the following OpticalStimulationConfig parameters:

Frame Format

An optical stimulation frame (OpticalStimFrame) describes a single image to display on the LED array. Each frame specifies:

Neuropixels 1.0

The Neuropixels 1.0 probe is a recording peripheral that can implement the Synapse Electrical Broadband node. Its NRIC1384 readout IC multiplexes 960 shank electrodes onto 384 recording channels.

One probe presents two Synapse peripherals that record simultaneously from the same electrodes: NRIC1384 for the action-potential (AP) band and NRIC1384-LFP for the local-field-potential (LFP) band. Each is configured independently, and both support the following ElectricalBroadbandConfig parameters:

The signal chain must supply an electrode configuration; a pixel configuration is rejected. Impedance measurement is not supported on this peripheral. Its self-test verifies that the base configuration loads and the probe asserts SR_OUT_OK.

Electrode Banks

The shank's 960 electrodes are grouped into three banks that share the probe's 384 recording channels:

An electrode maps to recording channel electrode_id modulo 384, so a configuration can select only one electrode per recording channel. Selecting electrodes 5 and 389 together is invalid because both land on channel 5. A configuration is also rejected when it repeats an electrode_id, exceeds 384 electrodes, or names electrode 191, 575, or 959, which are reference-only and cannot record.

Reference Selection

A Neuropixels 1.0 channel can reference one of three fixed nodes rather than an arbitrary electrode, so reference_id carries a reserved selector instead of an electrode ID:

Any other value is rejected. Only one internal-reference electrode is active across the probe, so a configuration cannot mix two different internal-reference banks.

AP High-Pass Corner

The probe's AP high-pass is a single on/off setting, so low_cutoff_hz selects between two corners:

• A value of 10 or less disables the high-pass and records full-band, leaving only the amplifier's own sub-1 Hz corner.
• A value above 10, or an empty field, engages the ~300 Hz AP high-pass.

The LFP band ignores low_cutoff_hz entirely.

Running Both Bands

The AP and LFP peripherals drive one physical probe, so their configurations must agree wherever they overlap. When both bands are running, a recording channel shared between them must select the same electrode and the same reference in each, and the two bands cannot request different internal-reference banks. gain remains independent per band.

Signal Scale

The probe digitizes with 10-bit ADCs and delivers samples as signed 16-bit values. The input-referred range is 1200 µV at a gain of 1000 and scales inversely with the configured gain, so raising the gain narrows the range and shrinks the value of one LSB.

Intan RHD2132

The Intan RHD2132 is a 32-channel recording peripheral that can implement the Synapse Electrical Broadband node. It appears as IntanRHD2132 and supports the following ElectricalBroadbandConfig parameters:

A configuration may enable up to 32 electrode channels, and the peripheral streams them in ascending electrode_id order regardless of the order you list them. Repeating an electrode_id is accepted and produces two channels that both sample the same amplifier. The peripheral's self-test reads the chip's ROM registers to confirm the INTAN signature and chip ID 0x01.

Sample Rate Quantization

The gateware derives the sample period from a fixed 80 MHz clock, so the achievable rates are 80 MHz divided by a whole number of clock cycles. The peripheral rounds the requested rate to the nearest achievable period and records at that rate, which can differ slightly from the value you requested. A request of 30000 Hz, for example, yields a period of 2667 cycles and an actual rate of about 29996 Hz. The frames report the actual rate.

Filter Corners

low_cutoff_hz and high_cutoff_hz set the chip's analog bandwidth. Both must be supplied together: a configuration that sets one and leaves the other empty is rejected, because a single corner would silently leave the other at its default. When both fields are empty, the chip records with its default 1 Hz to 7.5 kHz bandwidth.

Each value is snapped to the nearest corner the chip's register tables can produce:

GPIO Channels

The peripheral can sample up to three digital inputs alongside the electrode channels. A GPIO channel's electrode_id selects the input, 0 through 2; higher IDs are rejected because only those three are wired on the board. Duplicate GPIO IDs are also rejected.

GPIO samples arrive in the same frames as the electrode data, appended after the electrode channels, matching the channel ordering the NYX1-512 uses for its GPIO channels.

Impedance

This peripheral supports impedance measurement through the chip's on-chip impedance-check DAC. Measurements run per electrode, 0 through 31, and cannot run while the signal chain is recording. The stimulation frequency must be at least 250 Hz, and very high frequencies are rejected when a stimulation period becomes shorter than the measurement loop.

Sample Resolution

Samples are 16-bit two's complement. One LSB corresponds to 0.195 µV at the input, the datasheet's input-referred resolution at the chip's fixed 192 V/V gain. This value does not change with the filter corners.

SciFi Virtual Recording Peripheral

This recording peripheral generates test data for benchmarking and debugging SciFi headstages. It can implement the Electrical Broadband node. The peripheral will attempt to match the bit-rate requested by the supplied config parameters. It supports the following ElectricalBroadbandConfig parameters: