1. A memory hub device with test logic, the memory hub device configured to communicate with memory devices via multiple hub device ports and configured to communicate on one or more busses in an upstream and downstream direction, the test logic comprising: a configured command sequencer (CCS) to launch an architected command to a target device configurable between local execution of the architected command at the memory hub device and remote execution at one or more of: a downstream memory hub device and an upstream memory hub device; and configuration registers to hold fault and diagnostic information, and to initiate one or more tests.