April 1, 1981 STep Use the STep command to alter the contents of real storage. The real PSi or real registers cannot be altered with this command. In a system
running in attached processor data in shared pages cannot be modified by the use of this command. The format of the STep command is: STep hexloc
Khexloc
Nhexloc
Lhexloc
MLhexloc
NLhexloc Shexloc MShexloc NShexlOG I I I I I I , • I I I hexloc
Mhexloc
Nhexloc hexword1 [hexword2 ••• ]
Lhexloc
KLhexloc
NLhexloc
{ SheXIOC} KShexloc hexdata NShexloc stores the data given in hexword1 [hexword2 ••• ] in successive
fullword locations starting at the address specified by
hexloc. The smallest group of hexadecimal values that can be
stored using this specification is one full word. Data is
aligned to the nearest fullvord boundary. If the data being
stored is less than a fullword (eight hexadecimal digits), it
is right-adjusted in the word and the high order bytes of the
word are filled with zeros.
In attached processor systems, hexloe and Lhexloc values are
treated as absolute addresses. The letter K prefixing the
hexadecimal address causes that address to be interpreted
through the prefix register of the main processor. The letter
N prefixing an address functions the same way through the
prefix register for the attached processor. N is valid while
the attached processor is in operation. K is valid if the
system was generated for the attached processor mode of
operation.
stores the data given in hexdata in the address specified by
hexloc without vord alignment. The shortest string that can
be stored is one byte (two hexadecimal digits). If the string
contains an odd number of characters, the last character is
not stored. An error message occurs and the function ends.
148 VM/370 Operator's Guide

hexword
hexdata MShexloc and BShexloc operands are used in attached processor VM/370 applications. By prefixing Shex10c with! or H. the
specified hexadecimal addresses are interpreted through the
associated prefix registers of the main or the attached
processor, respectively.
specifies up to eight hexadeciaa1 digits. If less than eight
digits are specified, the string is right-justified in a
fu11word and left-filled with zeros. If two or lIore hexwords
are specified, they lIust be separated by at least one blank.
specifies a string of two or lIore hexadecimal digits with no embedded blanks. STCP H64 20000 stores 1'00020000' into the second word of the SVC new PSi in the PSI (prefix storage area) of the attached processor. STORE COMPLETE Section 3. CP COII.ands 149