To meet high requirements on availability, safety and tamper protection, the MicroBlaze™ processor can be implemented in a triple-redundant voting scheme. The method is often referred to as Triple Modular Redundancy (TMR). A MicroBlaze TMR subsystem is of Fault Tolerant - Fail Safe (FT-FS) type, which means that it continues to work without degradation after the first failure (FT) and will detect a second failure (FS).
The system in This Figure consists of a MicroBlaze processor with application code and data stored in block RAM. The I/O Module peripherals are connected to MicroBlaze through LMB. To implement an FT-FS scheme for this subsystem, it can be triplicated.
The MicroBlaze Debug Module (MDM) is not triplicated, and all the debug functionality is contained in the first of the three TMR sub-blocks, while the implementation prevents any error in this debug logic from propagating to the other sub-blocks. The triplicated I/O Module cores are interconnected to provide majority voting of their internal state.