  FlashCam is a Cherenkov camera development project centered around a fully
digital trigger and readout scheme with smart, digital signal processing, and a
"horizontal" architecture for the electromechanical implementation. The fully
digital approach, based on commercial FADCs and FPGAs as key components,
provides the option to easily implement different types of triggers as well as
digitization and readout scenarios using identical hardware, by simply changing
the firmware on the FPGAs. At the same time, a large dynamic range and high
resolution of low-amplitude signals in a single readout channel per pixel is
achieved using compression of high amplitude signals in the preamplifier and
signal processing in the FPGA. The readout of the front-end modules into a
camera server is Ethernet-based using standard Ethernet switches. In its
current implementation, data transfer and backend processing rates of ~3.8
GBytes/sec have been achieved. Together with the dead-time-free front end event
buffering on the FPGAs, this permits the cameras to operate at trigger rates of
up to several tens of kHz.
  In the horizontal architecture of FlashCam, the photon detector plane (PDP),
consisting of photon detectors, preamplifiers, high voltage-, control-, and
monitoring systems, is a self-contained unit, which is interfaced through
analogue signal transmission to the digital readout system. The horizontal
integration of FlashCam is expected not only to be more cost efficient, it also
allows PDPs with different types of photon detectors to be adapted to the
FlashCam readout system. This paper describes the FlashCam concept, its
verification process, and its implementation for a 12 m class CTA telescope
with PMT-based PDP.
