The gasket supports the following features for functional safety:
- CBA safety signaling on source and destination interfaces (if enabled with
<safe_bus> parameter)
- CBA safety signaling on configuration interface (if enabled with <safe>
parameter)
- ECC protection on scoreboard RAMs (if enabled with <safe> parameter)
- Parity protection on scoreboard flops (if enabled with <safe>
parameter)
- Parity protection or multi-bit field protection on configuration MMRs (if
enabled with <safe> parameter)
- Parity protection on the free-running timer (if enabled with <safe>
parameter)
An uncorrected error reported on any of the protected fields indicates a potentially
dangerous fault, and the system integrator should take appropriate action (such as
transition to a safe state).
A fault in the free-running timer may cause errors by prematurely timing out
transactions, but it may also be recoverable by taking the following steps.
- Disable the gasket.
- Wait for scoreboards to become empty. If they don’t become empty for a long
time, this may indicate that there are other issues in the system. The
system integrator can use Software Flush, but additional intervention is
probably required (such as transition to a safe state or system reset).
- Write a 0 to the Timer
Register (Base Address + 0x18) to reset the timer.
- Enable the gasket.