Abstract: A channel adapter monitoring device for tracing OEMI channel data and tags. The device is configurable via a support processor and supervisory microprocessor. A trace array memory stores events identified by a configurable write register. A timer is provided to permit a time stamp entry to be made with each data entry of detected events. The microprocessor can address the trace memory over an MMIO bus and recover the stored data for analysis.

Abstract: A device information interface for a channel to channel I/O device having a plurality of channel adapters. A device interface bus interconnects each of the channel adapters, permitting an exchange of data between channel adapters. A virtual device storage array at each channel adapter stores the status of inactive channel devices associated with a connected channel. Inquiries as to the status of a logical adapter may be sent over the device interface bus. Logic circuits at the receiving adapter will decode the inquiry and address the virtual storage array to obtain the status of the logical adapter for forwarding over the bus to the inquiring adapter.