701
Table Data Processing Instructions Section 3-17
SWRIT(640)
Writes the source data to the specified data element in the stack (overwriting
the existing data). The offset value indicates the location of the desired word
(the number of words before the current pointer position).
SINS(641)
Inserts the source data at the specified location in the stack and shifts the rest
of the data in the stack downward. The offset value indicates the location of
the desired word (the number of words before the current pointer position).
M
:
A
B
C
:
M
B
C
Stack
Data region
Pointer
Pointer
(Unchanged)
Last word of
data in stack
Stack
Data region
Pointer to last
word in stack
Data in pointer position - n
(n=3 in this example.)
Pointer
Overwrites data at pointer
position - n.
(n=3 in this example.)
-n
(n=3)
M
:
A
B
C
:
M
A
B
C
Stack
Data region
Pointer
Pointer
(Incremented by 1)
Last word of
data in stack
Stack
Data region
Pointer to last
word in stack
Data in pointer position - n
(n=3 in this example.)
Pointer
Inserts data element M at pointer
position - n, shifts the existing data
(A, B, and C) down, and increments
the pointer value by 1.
Pointer to last
word in stack
Pointer
-n
(n=3)
Insert
Data in pointer
position n