Abstract: The initialization process and structure of the system ensure that during loading of random data a 1-hot condition is maintained to the 1-hot multiplexer so as to prevent contention or a high current state. The present invention further improves observability of intermediate stages by preventing random data feeding of the state elements in scan chains that cannot tolerate random data. A scan chain having only scan registers that can receive random data is referred to as a LBIST Random Scan Chain (LRSC) and a scan chain having one or more scan registers that cannot tolerate and cannot receive random data is referred to as a “LBIST Non-random Scan Chain” (LNSC). A PRPG generates random data having a plurality of bit values to the LRSCs which is then passed to a multiple input shift register (MISR). The LNSCs do not receive random data from the PRPG but instead receive bit values from another scan chain.