Error Detection - Xilinx MicroBlaze Reference Manual

Chapter 2: MicroBlaze Architecture
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MicroBlaze Partition
DLMB
BRAM Controller
BRAM
ILMB
BRAM Controller
MicroBlaze
Debug Module
MicroBlaze Partition
DLMB
BRAM Controller
BRAM
ILMB
BRAM Controller
Debug Interface - Removed for Production

Error Detection

The error detection use case requires that all transient and permanent faults are detected. This is
essential in fail safe and fault tolerant applications, where redundancy is utilized to improve system
availability.
In this system two redundant MicroBlaze processors run in lockstep. A comparator is used to signal
an error when a mis-match is detected on the outputs of the two processors. Any error immediately
causes both processors to halt, preventing further error propagation.
The redundant MicroBlaze processors are functionally identical, except for debug logic and
associated signals.The outputs from the master MicroBlaze core drive the peripherals in the system.
The slave MicroBlaze core only has inputs connected; all outputs are left open.
The system contains the basic building block for designing a complete fault tolerant application,
where one or more additional blocks must be added to provide redundancy.
This use case is illustrated in
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C_LOCKSTEP_SLAVE = 0
MicroBlaze
Master
Debug
Lockstep_Master_Out
Lockstep_Slave_In
Debug
MicroBlaze
Slave
Lockstep_Out
C_LOCKSTEP_SLAVE = 1
Figure 2-26: Lockstep Tamper Protection Application
Figure
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Outputs
Inputs
Comparator Partition
Comparator
Lockstep_Out
Inputs
Comparator Partition
Comparator
2-27.
MicroBlaze Processor Reference Guide
Peripheral
Partition
I/O Interfaces
External Memory
Interfaces
UG081 (v14.7)