The following table and figure describe the four configuration options of the RPU.
|Configuration Option||Description||Core Running|
|Option 1: Split mode||High-performance mode.
In this configuration, both real-time cores work independently, each using separate TCMs.
|RPU core 0 and RPU core 1|
|Option 2: Split mode, only one core used||High-performance mode.
In this configuration, RPU core 0 can be held in reset, while RPU core 1 runs independently using all 256 KB of TCM.
|RPU core 1 only|
|Option 3: Lock-step mode||Safety mode.
Note: The lock-step mode is typically used for safety-critical deterministic applications.
In this configuration, both cores run in parallel with each other, with integrated comparator logic. The RPU core 0 is the master, and RPU core 1 is the checker.
The TCM is combined to give RPU core 0 a larger TCM.
Each core executes the same code. The inputs and outputs of the two cores are compared. If they do not match, then the comparator detects the error.
While two cores are used, the performance is of one core.
|RPU core 0 only|
|Option 4: None||RPU is not used.||None|
RPU cores can use the system watchdog timer (SWDT) to monitor functionality and check performance, through a periodic write to a timer register.
The following figure shows the resource sharing when the RPU cores are configured in lock-step mode.