CARMA/SZA Baseline Partitioning and FPGA Configuration Solutions
Kevin P. Rauch
Astronomy Dept, University of Maryland, College Park

Optimal fanout-minimized baseline-to-correlator card partitioning solutions 
for the 15-station CARMA and 8-station SZA arrays are described, as well as 
the method used to obtain them. For CARMA, implementation of the new solution 
requires 11 digitizer cards per band assuming a digitizer-only fanout 
solution, or 8 digitizer cards and 5 digital fanout boards assuming the latter
approach is used. The digital fanout boards require either 3 or 4 outputs 
depending on whether data is routed between correlator FPGAs at 125~MHz or 
62.5~MHz, respectively. The boards should be able to use the same physical 
form factor as the current COBRA digitizer cards. The new CARMA solution 
requires only 3 distinct correlator FPGA configurations, for which board-level
FPGA routing solutions are provided. No additional FPGA configurations are 
needed for the SZA correlator. Implications for the next-generation CARMA 
correlator are also discussed.