This circuit pack is built to manage errors that are linked with the EM-BUS and is required for use of the C-LAN (TN799) and NETpkt (TN794) circuit packs in R7 and later. The TN790 is a circuit pack level replacement for the TN786B/CPP1 combination. The mezzanine board for memory expansion is not supported.
There is an increase in performance over the TN786B/CPP1 combination because the RISC processor clocks at 40 MHZ and includes the functions of the TN786B processor while delivering an OS base that is more common with R7r. The Diagnostics are enhanced with the TN790 over earlier systems.