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Explore CREPE, a portable FPGA-based system enabling clocking, triggering, control, and readout features for Preshower Electronics. Key features include internal/external clocking and triggering, optical interfaces, Linux drivers, and LabVIEW support. Learn how to operate CREPE for efficient event handling and data transfer.
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Control & Readout Emulator for the Preshower Electronics (CREPE) P.Vichoudis, CERN
Introduction CREPE is a portable FPGA-based FE clocking/triggering/control/readout system • KEY FEATURES: • Internal/External clock operation • Internal/External triggering operation (incl. powerful trigger pattern generation) • Electrical/Optical control FE interface • Optical FE readout interface (up to 4ch.) • Operated by a single USB connection (max data rate 8Mbps) • For on-line readout, it supports an S-LINK transmitter (max data rate 2.4Gbps) • Device Drivers (for linux) • LabVIEW (for linux) template applications P.Vichoudis, CERN
Simplified Diagram P.Vichoudis, CERN
CREPE for Test Beam using only USB (1/2) P.Vichoudis, CERN
CREPE for Test Beam using only USB (2/2) Limitation: The system cannot receive events and send them to PC the same time. Operation 1. Arm the system – to be ready to accept triggers. 2. It will accept up to a certain number of events (at any rate) that fill the 2048-word buffers. 3. The buffers must be readout by the PC. No triggers should be sent in the buffer readout period. 4. Repeat steps 1-3 Arm Trigger Window Buffer Readout • - Trigger Window period: depends on the event rate & number of event that can fit in the buffer. • Buffer readout time: depends on the hardware access transaction time through USB. • It is also system depended (Operating system/PC speed etc). • The fastest time that can be achieved for reading out 1 CREPE’s buffer (1 data channel): • BRTmin = [usb transaction overhead] + [data size] / [USB data rate] = • BRTmin = ~2ms + 2048 x 32bit / (2.5Mbit/s) = ~27ms. • Note: the USB data rate measured in the lab is 2.5Mbit/s (instead of 8Mbit/s stated in the USB chipset manual). P.Vichoudis, CERN
Documentation CMS IN 2005/049 : “The control & readout emulator for the Preshower electronics (CRÊPE): users guide” LECC2004 Proceedings: “A flexible stand-alone testbench for facilitating system tests of the CMS Preshower” P.Vichoudis, CERN