MPE/iX Intrinsics Reference Manual (32650-90905)

Chapter 10 625
Command Definitions (QUIT-ZSIZE)
SWITCHDB
SWITCHDB
CM callable only.
Switches the DB register pointer. Privileged mode (PM) capability is required.
Syntax
U16 O-P U16V
logindex :=SWITCHDB( index )
Functional Return
logindex 16-bit unsigned integer (assigned functional return)
Returns the logical index of the data segment indicated by the previous
DB register setting, allowing this setting to be restored later. If the
previous DB setting indicated the stack, a zero is returned.
Parameters
index 16-bit unsigned integer by value (required)
Passes the logical index of the data segment where the DB register is to be
switched (obtained through the GETDSEG intrinsic). The value specified is
checked to ensure that the process has acquired access to the segment
previously. For an extra data segment, a positive, nonzero integer must be
specified. To switch to the stack segment, a zero must be specified.
Condition Codes
CCE (2) Request granted.
CCG (0) Not returned.
CCL (1) Request denied. An illegal data segment was specified.
Related Information
Intrinsics GETDSEG
Manual Introduction to MPE XL for MPE V Programmers