I have unique requirement that scan mode be set by internal register which would control output at PO. By default PI/PO which drives scan are set for something else. Before scan starts, I need to set register to a proper value so PI and PO controls inserted scan chain. I do know that there exist a way to have tester drive the Register interface to drive PI to set registers to desired value. What I do not now how to generate such pattern that tester understands and how to include them in initialization sequence.
Control registers are not part of ATPG cahins. Control registers need to be set to correct value to change few of the POs for SCAN mode. Do I have to convert SPI register write transaction in some form of scan sequence? If yes, how do I map them?