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      Copyright 2014-2015 The University of Hong Kong
            Copyright 2015-2016 / EnjoyDigital

        A small footprint and configurable SATA core
       developed for HKU by M-Labs Ltd & EnjoyDigital

[> Intro
---------
LiteSATA provides a small footprint and configurable SATA gen1/2/3 core.

LiteSATA is part of LiteX libraries whose aims are to lower entry level of
complex FPGA cores by providing simple, elegant and efficient implementations
of components used in today's SoC such as Ethernet, SATA, PCIe, SDRAM Controller...

The core uses simple and specific streaming buses and will provides in the future
adapters to use standardized AXI or Avalon-ST streaming buses.

Since Python is used to describe the HDL, the core is highly and easily
configurable.

LiteSATA is built using LiteX and uses technologies developed in partnership with
M-Labs Ltd:
 - Migen enables generating HDL with Python in an efficient way.
 - MiSoC provides the basic blocks to build a powerful and small footprint SoC.

LiteSATA can be used as LiteX library or can be integrated with your standard
design flow by generating the verilog rtl that you will use as a standard core.

[> Features
------------
PHY:
  - OOB, COMWAKE, COMINIT
  - ALIGN inserter/remover and bytes alignment on K28.5
  - 8B/10B encoding/decoding in transceiver
  - Errors detection and reporting
  - 32 bits interface
  - 1.5/3.0/6.0GBps supported speeds (respectively 37.5/75/150MHz system clk)
Core:
  Link:
    - CONT inserter/remover
    - Scrambling/Descrambling of data
    - CRC inserter/checker
    - HOLD insertion/detection
    - Errors detection and reporting
  Transport/Command:
    - Easy to use user interfaces (Can be used with or without CPU)
    - 48 bits sector addressing
    - 3 supported commands: READ_DMA(_EXT), WRITE_DMA(_EXT), IDENTIFY_DEVICE
    - Errors detection and reporting

Frontend:
  - Configurable crossbar (simply declare your crossbar and use crossbar.get_port() to add a new port!)
  - Ports arbitration transparent to the user
  - Synthetizable BIST
  - Striping module to segment data on multiple HDDs and increase write/read speed and capacity. (RAID0 equivalent)
  - Mirroring module for data redundancy and increase read speeds. (RAID1 equivalent)

[> Possible improvements
-------------------------
- add standardized interfaces (AXI, Avalon-ST)
- add NCQ support
- add AES hardware encryption
- add on-the-flow compression/decompression
- add support for Altera PHYs.
- add support for Lattice PHYs.
- add support for Xilinx 7-Series GTP/GTH (currently only 7-Series GTX are
  supported)
- add Zynq Linux drivers.
- ... See below Support and consulting :)

If you want to support these features, please contact us at florent [AT]
enjoy-digital.fr. You can also contact our partner on the public mailing list
devel [AT] lists.m-labs.hk.


[> Getting started
-------------------
1. Install Python3 and your vendor's software

2. Obtain LiteX and install it:
  git clone https://github.com/enjoy-digital/litex --recursive
  cd litex
  python3 setup.py install
  cd ..

3. Build and load BIST design (only for KC705 for now):
  go to example_designs
  run ./make.py all

4. Test design (only for KC705 for now):
  start remote_server (provided by LiteX, remote_server -h for help)
  go to example_designs/test
  run ./test_bist.py

5. If you only want to build the core and use it with your
   regular design flow:
     go to example_designs
     run ./make.py -t core build-core
   You can customize the core in example_designs/targets/core.py

[> Simulations
---------------
  Simulations are available in ./test:
    - crc_tb
    - scrambler_tb
    - phy_datapath_tb
    - link_tb
    - command_tb
    - bist_tb
  Models for all the layers of SATA and a simplified HDD model are
  provided.
  To run a simulation:
    go to test/
    make <simulation_name>

[> Tests
---------
  A synthetizable BIST is provided and can be controlled with the bist.py script.
  By using LiteScope and the provided test_analyzer.py example you are able to
  visualize the internal logic of the design and even inject the captured data in
  the HDD model!

[> License
-----------
LiteSATA is released under the very permissive two-clause BSD license. Under the
terms of this license, you are authorized to use LiteSATA for closed-source
proprietary designs.
Even though we do not require you to do so, those things are awesome, so please
do them if possible:
 - tell us that you are using LiteSATA
 - cite LiteSATA in publications related to research it has helped
 - send us feedback and suggestions for improvements
 - send us bug reports when something goes wrong
 - send us the modifications and improvements you have done to LiteSATA.

[> Support and consulting
--------------------------
We love open-source hardware and like sharing our designs with others.

LiteSATA is developed and maintained by EnjoyDigital.

If you would like to know more about LiteSATA or if you are already a happy user
and would like to extend it for your needs, EnjoyDigital can provide standard
commercial support as well as consulting services.

So feel free to contact us, we'd love to work with you! (and eventually shorten
the list of the possible improvements :)

[> Contact
E-mail: florent [AT] enjoy-digital.fr