pTAL Conversion Guide

pTAL Built-In Routines
pTAL Conversion Guide—527302-002
18-53
$WADDR_TO_BADDR
unlockcount input
sINT:value
is the total number of bytes to unlock in the page.
virtaddr input
EXTADDR:value
is the beginning virtual address to unlock. $UNLOCKPAGE calculates the page
associated with virtaddr.
$UNLOCKPAGE is for exclusive use of the operating system’s memory manager.
Privileged programs must use the UNLOCKMEMORY procedure to unlock memory.
$WADDR_TO_BADDR
$WADDR_TO_BADDR converts a WADDR address to a BADDR address.
expression
is an expression whose value is a WADDR address.
$WADDR_TO_BADDR returns expression converted to a BADDR address.
Figure 18-23. TAL Code Equivalent to $UNLOCKMEMORY Routine
STACK unlockcount, addr;
CODE(ULKX);
Example 18-38. Call to $UNLOCKPAGE Routine
INT unlockcount;
EXTADDR addr;
$UNLOCKPAGE(unlockcount, addr);
pTAL privileged procedure No
Can be executed only by privileged procedures No
Sets condition code No
Sets $CARRY No
Sets $OVERFLOW No
expression( )
VST691.vsd
$WADDR_TO_BADDR