System Debug Reference Manual (32650-90888)

ManualsBrandsHP ManualsSoftwareMPE/iX 6.5 Operating System

Chapter 2 35

User Interface

Operators

Address speciﬁcations for the indirection operator contain an

address mode keyword

. All

address modes can be used in both NM and CM.

The default address mode is VIRT (NM virtual address). Virtual addresses can be speciﬁed

as short pointers, long pointers, or full NM logical code addresses.

REAL mode addresses physical memory in the HP Precision Architecture machine.

SEC mode addresses secondary storage. The address is always speciﬁed in the form of a

long pointer or extended address to indicate the LDEV and byte offset.

VIRT, REAL, and SEC mode addresses are always automatically 4-byte-aligned (backwards

to the nearest NM word boundary) before any data is retrieved. The indirect contents

result value is returned as a signed 32-bit (S32) value.

Additional address modes provide access to compatibility mode data structures. In these

modes, addresses are interpreted as CM word (16-bit-alignment) addresses, and the

indirect contents result value is returned as a signed 16-bit (S16) value. The following CM

modes are supported:

• ABS mode accesses emulated compatibility mode bank 0 addresses. This terminology is

derived from absolute memory addressing in the HP 3000 architecture.

• DL mode addresses are DL-relative.

• DB mode addresses are DB-relative.

• Q mode addresses are Q-relative.

• S mode addresses are S-relative.

• P mode addresses are P-relative.

• DST mode accesses a word at the speciﬁed data segment and offset.

• CST mode accesses a word at the speciﬁed CST code segment and offset.

• CSTX mode accesses a word at the speciﬁed CSTX code segment and offset.

Since the default addressing mode is VIRT, a special CM mode CMLOG is provided to

indicate that the address is a full CM logical code address.

[S[

offset

]]

S16 2 bytes

[P[

offset

]]

S16 2 bytes

[DST[

dst.offset

]]

S16 2 bytes

[CST[

cst.offset

]]

S16 2 bytes

[CSTX[

cstx.offset

]]

S16 2 bytes

[CMLOG[

lcptr

]]

S16 2 bytes

Table 2-4. Indirection Operator Syntax

Indirection Default Alignment Return Type