The SN74ACT8994 digital bus monitor (DBM) is a member of the Texas Instruments SCOPETM?testability integrated-circuit family. This family of components supports IEEE Standard 1149.1-1990 (JTAG) boundary scan to facilitate testing of complex circuit-board assemblies. The DBM is a boundary-scannable device designed to monitor and/or store the values of a digital bus up to 16 bits in width. It resides in parallel with the bus being monitored.