SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
To implement a lockstep CPU cluster, a diagnostic checker block is included. The diagnostic checker block compares the CPU compare outputs on every cycle. A difference in the CPU output signals is indicated by an error signal.
As the CPUs are working with a two-cycle phase difference, there should be no compare errors generated when the CPUs are reset two cycles apart. For the various CPU interfaces, the comparison will start on the first valid transaction on key control signals.