NonStop S-Series Server Description Manual (G06.24+)

TNS Instruction Set
HP NonStop S-Series Server Description Manual—520331-003
11-40
Definitions of TNS Instructions
SSW (000027). Store A Into Switch Register. The contents of the A register are set
into sysstack[%122]. A is then deleted. This instruction is nonprivileged even though it
alters an SG cell.
STAR (00011-). Store A in a Register. The A register contents are stored in the
register pointed to by the Register field of the instruction. A is then deleted from the
stack. (For binary coding details, refer to Table B-5 on page B-5.)
STB (-54---). Store Byte From A to Data Space. The contents of the byte in bits 8:15
of A are stored in the effective memory location.
STD (-64---). Store Doubleword From BA Into Data Space. The contents of BA are
stored in the effective memory location. BA is deleted. Figure 11-2 on page 11-3
illustrates the addressing methods for doubleword instructions. For binary coding
details, refer to Table B-1 on page B-1.
STOR (-44---). Store A Into Data Space. The contents of the A register are stored into
the effective memory location. A is then deleted from the stack. For binary coding
details, refer to Table B-1 on page B-1.
STRP (00010-). Set RP. The register pointer is set to the value in the register field of
the instruction. For binary coding details, see Table B-5 on page B-5.
SWA (000361). Store Word via A. The word contained in B is stored into the effective
memory location pointed to by the address in A. Both words are then deleted from the
stack. SWA accesses the current data segment only.
SWAS (000351). Store Word via A Into System. The word contained in B is stored
into the effective memory location pointed to by the address in A. Both words are then
deleted from the stack. A refers to an address in the system data segment.
SWX (000411). Store Word Extended. The word in register C is stored into the
memory location specified by the 32-bit even-byte address in registers B and A. C, B,
and A are then deleted.
SWXX (0255--, 0265--). Store Word Extended, Indexed. The word contained in B is
stored into a computed memory location. The memory address is obtained as follows.
The displacement value (0 through 63) in bits 10 through 15 of the instruction word is
added to a base value, which is either G[0] (coded 0255--) or the current L register
value (coded 0265--); the data word so indicated is assumed to be the first word of a
two-word even-byte extended memory pointer. The index value in A is sign-extended,
then shifted left one bit position (multiplication by 2, because this instruction requires
word addressing rather than byte addressing), and then added to the extended
memory pointer to address the location that is to receive the word being stored. For
binary coding details, refer to Table B-3 on page B-3.
XCAL (127---). External Procedure Call. The XCAL instruction is used to invoke
procedures that are outside the current code segment. Like PCAL, XCAL creates a
three-word stack marker. Then control is transferred to an instruction in the external
segment by a three-step sequence: (1) a number in the XEP field of the instruction
refers to an entry in the XEP table of the current code segment, (2) the XEP entry
specifies a segment and a PEP entry in that segment, and (3) the PEP entry of the