Reset recovery/removal timing requirements come from the fact that, in any system with asynchronous reset, Reset can be asserted asynchronously regardless of clock event but it should be released in synchronous manner keeping below requirements in check.
Note: Here reset assertion means applying reset and reset release/deassertion means coming out of the reset.
Reset Recovery Time - Minimum time period before active clock edge, before which Reset is released. This is similar to Setup time requirement in FF. Basically one should not release Reset signal in this time frame.
Reset Removal Time - Minimum time period after active clock edge where Reset signal can be released. This is similar to Hold time requirement in FF. Reset should not be released in this time frame.
Note: Here reset assertion means applying reset and reset release/deassertion means coming out of the reset.
Reset Recovery Time - Minimum time period before active clock edge, before which Reset is released. This is similar to Setup time requirement in FF. Basically one should not release Reset signal in this time frame.
Reset Removal Time - Minimum time period after active clock edge where Reset signal can be released. This is similar to Hold time requirement in FF. Reset should not be released in this time frame.
