A Real Time Electronics Emulator with Realistic Data Generation for Reception Tests of the CMS ECAL Front-End Boards

The CMS [1] electromagnetic calorimeter (ECAL) [2] uses 3 132 Front-End boards (FE) performing both trigger and data readout functions. Prior to their integration at CERN, the FE boards have to be validated by dedicated test bench systems. The final one, called "XFEST" (eXtended Front-End System Test) and for which the present developments have been performed, is located at Laboratoire Leprince-Ringuet. In this contribution, a solution is described to efficiently test a large set of complex electronics boards characterized by a large number of input ports and a high throughput data rate. To perform it, an algorithm to simulate the Very Front End signals has been emulated. The project firmwares use VHDL embedded into XILINX Field Programmable Gate Array circuits (FPGA). This contribution describes the solutions developed in order to create a realistic digital input patterns real-time emul ator working at 40 MHz. The implementation of a real time comparison of the FE output streams as well as the test bench will be also presented.