.. _onidatasheet_ostim_hs64:

HS64 Optical Stimulator
###########################################
:Authors: Jie (Jack) Zhang & Jonathan P. Newman
:Version: 1
:IO: Register Access
:ONIX ID: 5
:ONIX Hubs: :ref:`headstage_64`

Description
*******************************************
The **HS64 Optical Stimulator** is a two-channel high-current LED/laser diode
driver for optogenetic stimulation (On Semi CAT4016). The maximal current can
be set over a wide (~10 mA to 800 mA) range via an external digital
potentiometer. The optical power can then be adjusted linearly and
synchronously across both channels within this range over 8-levels per diode
load. This sub-circuit is controlled as a single device using parameters
similar to a Master8 or `PulsePal <https://open-ephys.org/pulsepal>`__.

Register Programming
*******************************************

.. list-table:: HS64 Optical Stimulator Registers
    :widths: auto
    :header-rows: 1
    :name: ostim-hs64-regs

    * - Address
      - Name
      - Access
      - Time of Effect
      - POR Value
      - Reset Action
      - Description

    * - 0x00
      - NULLPARM
      - R
      - N/A
      - 0
      - None
      - No effect.

    * - 0x01
      - MAXCURRENT
      - R/W
      - Immediate
      - 200
      - None
      - Max LED/LD current, (0 to 255 = 800mA to 0 mA. See fig 10 of CAT4016 datasheet)

    * - 0x02
      - PULSEMASK
      - R/W
      - Immediate
      - (others => '1')
      - None
      - Bitmask determining which of the (up to 32) channels is affected by trigger

    * - 0x03
      - PULSEDUR
      - R/W
      - Immediate
      - 1000
      - None
      - Pulse duration, microseconds

    * - 0x04
      - PULSEPERIOD
      - R/W
      - Immediate
      - 50000
      - None
      - Inter-pulse interval, microseconds

    * - 0x05
      - BURSTCNT
      - R/W
      - Immediate
      - 5
      - None
      - Burst duration, number of pulses in burst

    * - 0x06
      - IBI
      - R/W
      - Immediate
      - 1000000
      - None
      - Inter-burst interval, microseconds

    * - 0x07
      - TRAINCNT
      - R/W
      - Immediate
      - 1
      - None
      - Pulse train duration, number of bursts in train, 0 = continuous

    * - 0x08
      - TRAINDELAY
      - R/W
      - Immediate
      - 0
      - None
      - Pulse train delay, microseconds

    * - 0x09
      - TRIGGER
      - R/W
      - Immediate
      - 0
      - Default
      - Trigger stimulation (1 = deliver)

    * - 0x0a
      - ENABLE
      - R/W
      - Immediate
      - 0
      - Default
      - 1: enables the stimulator, 0: stimulator ignores triggers (so that a common trigger can be used)

    * - 0x0b
      - RESTMASK
      - R/W
      - Immediate
      - (others => '0')
      - None
      - Bitmask determining the "off" state of the up to 32 channels

    * - 0x0c
      - RESET
      - R/W
      - Immediate
      - 0
      - None
      - If 1, Reset all parameters to default

    * - 0x0d
      - MINRHEOR
      - R
      - Immediate
      - MINRHEOR
      - Default
      - The series resistor between the potentiometer (rheostat) and RSET bin on the CAT4016

    * - 0x0e
      - POTRES
      - R
      - Immediate
      - POTRES
      - Default
      - The resistance value of the potentiometer connected in rheostat config to RSET on CAT4016

A graphical register definitions are provided in the following diagrams:

.. figure:: /_static/images/device_hs64-ostim/ostim-hs64_parameters.png
    :align: center
    :scale: 50%

    A diagram of the stimulus parameters presented in the
    :ref:`ostim-hs64-regs` table.

Device To Host Data Frames
******************************************
No frames are transmitted to the host.

Host To Device Data Frames
******************************************
This device does not accept input frames. All write attempts will fail with an
error.