DIGITAL DEVICE

摘要

A digital device (10) comprising one or more requestor units (12A, 12B), one or more responder units (14A, 14B, 14C), and a bus (16) is described. Each responder unit (14A, 14B, 14C) is connected to the requestor units (12A, 12B) via the bus (16). Each responder unit (14A, 14B, 14C) comprises a plurality of responder elements (18_1— 18_9) which are accessible by the requestor units (12A, 12B) via the bus (16) and which include one or more critical responder elements (18_1, 18_2, 18_5). The digital device (10) further comprises one or more wrapper units (20A, 20B, 20C). Each wrapper unit (20A, 20B, 20C) connects one of the responder units (14A, 14B, 14C) to the bus (16). Each wrapper unit comprises: an interface unit (22) arranged to enable the requestor units (12A, 12B) to access the responder elements (18_1— 18_9) of the respective responder unit (14) associated with the respective wrapper unit (20A). Each wrapper unit further comprises a checksum unit (26) arranged to respond to any write access to any one (18_2) of the critical responder elements (18_1, 18_2, 18_5) by computing and storing a reference checksum; wherein the checksum unit (26) is arranged to compute the reference checksum by applying a checksum algorithm to a subset of the critical responder elements (18_1, 18_2, 18_5), the subset comprising at least the write-accessed critical responder element (18_2).