sb_bits
row = sb_bits(rank_addr, rowbits, sb_close_row);
col = sb_bits(rank_addr, colbits, sb_close_column);
row = sb_bits(rank_addr, rowbits, sb_open_row);
col = sb_bits(rank_addr, colbits, sb_open_fine_column);
col = sb_bits(rank_addr, colbits, sb_open_column);