This work applies weight based codes to the detection of crosstalk originated errors. This type of fault, whose importance grows with device scaling may originate errors that are undetectable by the commonly used error detecting codes in VLSI ICs. Conversely, such errors can be easily detected by weight based codes that, however, have smaller encoding capabilities. In order to reduce the cost of these codes, a graph theoretic optimization is used. Moreover new applications of these codes are explored regarding the synthesis of self-checking FSMs, and the detection of errors related to the clock distribution network. © 2001 IEEE.