The idle state is similar to the observation state, except that the controller does not observe the FPGA configuration system for indication of error conditions. The idle state is indicated by the deassertion of all five state bits on the Status Interface. If the controller receives a command (from either the Error Injection Interface or the Monitor Interface), then the controller processes the received command. The error injection and software reset commands are only supported in the idle state.
The “enter observation” command can be applied through either the Error Injection Interface or the Monitor Interface, and is used to return the controller to the observation state so that errors can be detected.
The “status report” command provides some diagnostic information, and can be helpful as a mechanism to “ping” the controller. This command is only supported on the Monitor Interface.
Any desired set of “error injection” commands can be applied through either the Error Injection Interface or the Monitor Interface. These commands direct the controller to perform error injections. The primary reason the idle state exists is to halt actions taken in response to error detections so that multi-bit errors can be constructed.
The software reset command can also be applied through either the Error Injection Interface or the Monitor Interface. This command directs the controller to perform a software reset.