SPARC Assembly Language Reference Manual

E.1.2 Alternate Space Access

Load- and store-alternate instructions to one-half of the alternate spaces can now be included in user code. In SPARC-V9, loads and stores to ASIs 0016 .. 7f16 are privileged; those to ASIs 8016 .. FF16 are nonprivileged. In SPARC-V8, access to alternate address spaces is privileged.