The following assembler instructions provide the control capabilities and information a program needs for synchronous cross memory communication. For a detailed explanation of the following instructions, see Principles of Operation.

• EPAR (extract primary ASN) - Places the ASID of the primary address space into a general purpose register (GPR).
• EPAIR (extract primary ASN and instance) - Places the ASID and instance number of the primary address space into a general purpose register (GPR). Bits 0-31 of the GPR contain the instance number and bits 48-63 contain the ASID.
• ESAR (extract secondary ASN) - Places the ASID of the secondary address space into a general purpose register.
• ESAIR (extract secondary ASN and instance) - Places the ASID and instance number of the secondary address space into a general purpose register (GPR). Bits 0-31 of the GPR contain the instance number and bits 48-63 contain the ASID.
• IAC (insert address space control) - Indicates, in a general purpose register, the current ASC mode.
• MVCK (move with key) - Moves data between storage areas that have different storage protection keys.
• MVCP (move to primary) - Moves data from the secondary address space to the primary address space.
• MVCS (move to secondary) - Moves data from the primary address space to the secondary address space.
• PC (program call) - Invokes the program identified by the specified PC number. There are two types of PC linkages, basic and stacking. Both linkages transfer control to another program, the PC routine. The stacking PC, however, provides more capability and better performance than the basic linkage. The PC routine that receives control can be in an address space other than the address space in which the PC instruction was issued.
• PR (program return) - Returns control to a program that issued a stacking PC instruction.
• PT (program transfer) - Returns control to a program that issued a basic PC.
• PTI (program transfer with instance) - Return control to a program that issued a basic PC.
• SAC (set address space control) - Explicitly sets the ASC mode.
• SSAR (set secondary ASN) - Sets the secondary address space to the desired address space.
• SSAIR (set secondary ASN and instance) - Sets the secondary address space and instance number to the desired address space and instance number.