File structure

This is the file tree of qcrypto as of 29 September 2022.

├───errorcorrection
├───hardware
│   ├───electronics
│   └───timestampfirmware
├───readevents4
├───remotecrypto
│   └───data
│       └───blinding
├───timestamp3
├───timestamp7
│   └───lookuptables
└───usbtimetagdriver
    ├───designstuff
    ├───driver
    └───hotplug

errorcorrection

Contains all code used in the error correction step of the QKD protocol. See this for an overview of what the code is doing.

hardware

Contains circuit diagrams and firmware for the timestamp.

readevents4

Older version of readevents code.

remotecrypto

Main workhorse of qcrypto. Contains multiple C programs that process timestamp data obtained from readevents program. See this for an overview of what the code is doing.

timestamp3

LEGACY CODE

This is a usb version of the readevents program, used for generating a stream of consolidated timestamp events from ver. 3 of the timestamp card. This program is the interface to a timestamp card, cleans up some bitorder issues and allows to add detector time skews and/or a correction to a system time of the host PC.

Files contained in this directory:

readevents3.c     main code for timestamp card reader

timetag_io2.c     functions close to the hardware

timetag_io2.h     header definition for main program

usbtimetagio.h    definitions of commands used both for ioctls() to the device driver and to the firmware in the USB timestamp card

makefile

Other files and information necessary to understand this better:

  1. Circuit diagram, functional description of the timestamp card

  2. Firmware of the USB interface, based on a Cypress FX2 chip. Code in directory sdcc/test3, program tp_7.c and friends. Needs serious cleanup.

  3. USB device driver for the timestamp card, in usbtimetagdriver directory

timestamp7

Contains latest readevents program, used for generating a stream of consolidated timestamp events from a timestamp card. The files in this directory are listed below with a brief description. View the docstrings in the main code file for a more detailed description.

Files contained in this directory:

makefile

configtmst.h        FPGA configuration register for the timestamp test unit

powerplay.c         Program to test the power bit (Turns the power supply to the timestamp card on/off)

readevents5.c       Reads in events from ver. 5 of the timestamp card

readevents6.c       Reads in events from ver. 6 of the timestamp card

readevents7.c       Reads in events from ver. 7 of the timestamp card

showdiff.c          Test code to show time difference between events

timestampcontrol.h  Commands to interface with the test timestamp unit

usbtimetagdriver

Contains usb driver for the timestamp card, some installation scripts and testing software for that driver.