pTAL Conversion Guide

pTAL Built-In Routines
pTAL Conversion Guide—527302-002
18-35
$MOVEANDCXSUMBYTES
lock-count input
sINT:value
is the total number of bytes to lock in the page.
virtaddr input
EXTADDR:value
is the beginning virtual address to lock. $LOCKPAGE calculates the page
associated with virtaddr.
$MOVEANDCXSUMBYTES
$MOVEANDCXSUMBYTES transfers a specified number of bytes from one location in
extended memory to another, and computes a checksum (bytewise exclusive “or”) on
the bytes moved.
Figure 18-13. TAL Code Equivalent to $LOCATESPTHDR Routine
STACK only_if_locked, lock_count, virtaddr;
CODE(LCKX);
Example 18-24. Call to $LOCKPAGE Routine
INT only_if_locked;
INT lock_count;
EXTADDR virtaddr;
$LOCKPAGE(only_if_locked, lock_count, virtaddr);
pTAL privileged procedure No
Can be executed only by privileged procedures No
Sets condition code No
Sets $CARRY No
Sets $OVERFLOW No
$MOVEANDCXSUMBYTES (
checksum
,
),, ;destaddr srcaddr count
VST647.vsd