In this example a SVF file is developed for an ASIC. The ASIC is then placed in a board as u3, shown below:
The set of SVF statements originally developed for the ASIC can be reused with minimal modification if the appropriate header and trailer statements are defined to accommodate the devices in front of and behind u3. In this example, a header pattern would be defined for devices u4 and u5, and a trailer pattern would be defined for u2 and u1. The optional parameters can be specified in any order. Each optional parameter can only be specified once. Hex strings specified for TDI, TDO, MASK, or SMASK cannot be a value larger than the maximum implied by the length parameter. Leading zeros are assumed for a hex string if not explicitly specified.