Subregion Assignment Memory Data Format
Field	Even TECs	Odd TECs
<12:10>	TEC 6	latched but not used
<9:7>	TEC 4	TEC 5
<6:4>	TEC 2	TEC 3
<3:0>	TEC 0	TEC 1
Each data field indicates the subregion 0-7 for that tower