  The Beijing Spectrometer (BESIII) is an experimental setup located at the
Beijing Electron Positron Collider (BEPCII). The recently approved ten-year
extension of data acquisition for BESIII prompted an upgrade program for both
the BEPCII collider that houses the experiment and some of the sub-detectors
that make up the spectrometer. The current inner drift chamber is suffering
from aging and it has been proposed to replace it with a detector based on the
Cylindrical Gas Electron Multiplier (CGEM) technology.
  The CGEM Inner Tracker (CGEM-IT) consists of three coaxial layers of triple
GEM. The lightweight tracker is designed to recover efficiency and improve
z-determination and secondary vertex position reconstruction, resulting in a
better performance and longer lifetime. A novel system has been deeloped for
the readout of the CGEM detector, including a new ASIC, called TIGER (Torino
Integrated GEM Electronics for Readout), designed to amplify and digitize the
CGEM signals. The data output from TIGER are collected and processed by a first
FPGA-based module, GEM Read Out Card, which is responsible for configuring and
controlling the front-end ASICs. A second FPGA-based module, GEM Data
Concentrator (GEM DC), builds the event packets and transmits them to the
BESIII data acquisition system.
  In this thesis I will describe the entire custom electronics chain designed
for the CGEM-IT to achieve the desired performance.
  The structure of my work is presented along with the results of the
measurements performed on the detector and the analysis of the data obtained
with the detection of cosmic rays and under test beam.
