This indicates the maximum value that hh3cSecureNumberAddresses
can be set to. It is dependent on the resources available so may change,
eg. if resources are shared between ports, then this value can both
increase and decrease. This object must be read before setting
hh3cSecureNumberAddresses.
Those objects are bound by the relationship:
hh3cSecureNumberAddressesStored <= hh3cSecureNumberAddresses <=
hh3cSecureMaximumAddresses