Amazon.com, Inc.
Auto-detection of interconnect hangs in integrated circuits

Abstract:

A self-detection mechanism for an IC is disclosed that determines whether the IC's internal bus is in a hanging state. An initialization sequence can be modified after a soft reset by reading data from an internal DRAM of the IC using a Direct Memory Access (DMA) controller as part of the initialization sequence. The read command is issued over the internal bus and, if the bus is hanging, the read command is not completed. Monitoring can be performed by waiting a predetermined period of time (e.g., 100 ms) to determine if the read was properly completed. If so, no further action is needed. If the read was not completed, then a hard reset is requested to be performed. Thus, an initialization sequence can be modified to run dummy transactions through the internal bus, and validate that all paths are functional.