Firmware upgrade for the data acquisition system of the LabPET™ small animal PET scanner

The LabPET scanner is based on avalanche photodiodes individually read out by free running analog to digital converters, giving it the ability to reach high count rates for individual detection crystal. The actual rate performance depends on the supporting firmware that implements the detection, sampling and processing steps in the host programmable devices. The initial firmware version for the LabPET provided the target performance, but was written for functionality rather than maximum throughput. The upgraded firmware reorders and tweaks several parts of the analysis flow and uses pipelining techniques to increase count rate performance by 50%, while utilizing 24% less FPGA logic resources and no hardware modifications. This releases enough space to fit an embedded histogramming module for individual channels to be used in special experimental setups.