artiq/README_PHASER.rst

ARTIQ Phaser
============

This ARTIQ branch contains a proof-of-concept design of a GHz-datarate multichannel direct digital synthesizer (DDS) compatible with ARTIQ's RTIO channels.
In later developments this proof-of-concept can be expanded to provide a two-tone output with spline modulation and multi-DAC synchronization.
Ultimately it will be the basis for the ARTIQ Sayma Smart Arbitrary Waveform Generator project. See https://github.com/m-labs/sayma and https://github.com/m-labs/artiq-hardware.

*Features*:

* up to 4 channels
* up to 500 MHz data rate per channel (KC705 limitation)
* up to 8x interpolation to 2.4 GHz DAC sample rate
* Real-time control over amplitude, frequency, phase of each channel through ARTIQ RTIO commands
* Full configurability of the AD9154 and AD9516 through SPI with ARTIQ kernel support
* All SPI registers and register bits exposed as human readable names
* Parametrized JESD204B core (also capable of operation with eight lanes)
* The code can be reconfigured. Possible example configurations are: support 2 channels at 1 GHz datarate, support 4 channels at 300 MHz data rate, no interpolation, and using mix mode to stress the second and third Nyquist zones (150-300 MHz and 300-450 MHz).

The hardware required to use the ARTIQ phaser branch is a KC705 with an AD9154-FMC-EBZ plugged into the HPC connector and a low-noise sample rate reference clock.

This work was supported by the Army Research Lab.

The code that was developed for this project is located in several repositories:

* In ARTIQ, the SAWG and Phaser code: https://github.com/m-labs/artiq/compare/phaser
* The CORDIC core has been reused from the PDQ2 gateware https://github.com/m-labs/pdq2
* The Migen/MiSoC JESD204B core: https://github.com/m-labs/jesd204b


Installation
------------

These installation instructions are a short form of those in the ARTIQ manual.
Please refer to and follow the ARTIQ manual for more details:
https://m-labs.hk/artiq/manual-release-2/index.html

* Set up a new conda environment and activate it.
* Install the standard ARTIQ runtime/install dependencies.
  See ``conda/artiq/meta.yaml`` for a list.
  They are all packaged as conda packages in ``m-labs/main``.

* Install the standard ARTIQ build dependencies.
  They are all available as conda packages in m-labs/main or m-labs/dev for linux-64:

  - migen =0.4
  - misoc =0.4
  - llvm-or1k =3.8
  - rust-core-or1k
  - cargo
  - binutils-or1k-linux >=2.27

* Install a recent version of Vivado (tested and developed with 2016.2).
* Checkout the ARTIQ phaser branch and the JESD204B core: ::

    mkdir ~/src
    cd ~/src
    git clone --recursive -b phaser https://github.com/m-labs/artiq.git
    git clone https://github.com/m-labs/jesd204b.git
    cd jesd204b
    python setup.py develop
    cd ../artiq
    python setup.py develop


Setup
-----

* Setup the KC705 (jumpers, etc.) observing the ARTIQ manual.
  VADJ does not need to be changed.
* On the AD9154-FMC-EBZ put jumpers:

  - on XP1, between pin 5 and 6 (will keep the PIC in reset)
  - on JP3 (will force output enable on FXLA108)

* Compile the ARTIQ Phaser bitstream, bios, and runtime (c.f. ARTIQ manual): ::

    python -m artiq.gateware.targets.kc705 -H phaser --toolchain vivado

* Run the following OpenOCD command to flash the ARTIQ phaser design: ::

    openocd -f board/kc705.cfg -c "init; jtagspi_init 0 bscan_spi_xc7k325t.bit; jtagspi_program misoc_phaser_kc705/gateware/top.bin 0x000000; jtagspi_program misoc_phaser_kc705/software/bios/bios.bin 0xaf0000; jtagspi_program misoc_phaser_kc705/software/runtime/runtime.fbi 0xb00000; xc7_program xc7.tap; exit"

  The proxy bitstream ``bscan_spi_xc7k325t.bit`` can be found at https://github.com/jordens/bscan_spi_bitstreams or in any ARTIQ conda package for the KC705.
  See the source code of ``artiq_flash.py`` from ARTIQ for more details.

  If you are using the OpenOCD Conda package:

  * locate the OpenOCD scripts directory with: ``python3 -c "import artiq.frontend.artiq_flash as af; print(af.scripts_path)"``
  * add ``-s <scripts directory>`` to the OpenOCD command line.

* Refer to the ARTIQ documentation to configure an IP address and other settings for the transmitter device.
  If the board was running stock ARTIQ before, the settings will be kept.
* A 300 MHz clock of roughly 10 dBm (0.2 to 3.4 V peak-to-peak into 50 Ohm) must be connected to the AD9154-FMC-EBZ J1.
  The external RTIO clock, DAC deviceclock, FPGA deviceclock, and SYSREF are derived from this signal.
* An example device database, several status and test scripts are provided in ``artiq/examples/phaser/``. ::

    cd artiq/examples/phaser

* Edit ``device_db.pyon`` to match the hostname or IP address of the core device.
* The ``startup_clock`` needs to be set to internal (``i``) for bootstrapping the clock distribution tree.
* Compile and flash the startup kernel in ``artiq/examples/phaser/startup_kernel.py``.
* Erase any possible idle kernels.
* Use ``ping`` and ``flterm`` to verify that the core device starts up and boots correctly.

Usage
-----

* After each boot, run the ``dac_setup.py`` experiment to establish the JESD204B links (``artiq_run repository/dac_setup.py``).
* Run ``artiq_run repository/ad9154_test_status.py`` to retrieve and print several status registers from the AD9154 DAC.
* Run ``artiq_run repository/ad9154_test_prbs.py`` to test the JESD204B PHY layer for bit errors. Reboot the core device afterwards.
* Run ``artiq_run repository/ad9154_test_stpl.py`` to executes a JESD204B short transport layer test.
* Run ``artiq_run repository/sawg.py`` for an example that sets up amplitudes, frequencies, and phases on all four DDS channels.
* Run ``artiq_run repository/demo.py`` for an example that exercises several different use cases of synchronized phase, amplitude, and frequency updates.
  for an example that exercises several different use cases of synchronized phase, amplitude, and frequency updates.
* Implement your own experiments using the SAWG channels.
* Verify clock stability between the sample rate reference clock and the DAC outputs.
* Changes to the AD9154 configuration can also be performed at runtime in experiments.
  See the example ``dac_setup.py``.
  This can e.g. be used to enable and evaluate mix mode without having to change any other code (bitstream/bios/runtime/startup_kernel).