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Table Data Processing Instructions Section 3-15
3-15 Table Data Processing Instructions
Instruction
Mnemonic
Code
Symbol/Operand Function Location
Execution
condition
SET STACK
SSET
@SSET
630
Output
Required
PUSH ONTO
STACK
PUSH
@PUSH
632
Output
Required
LAST IN FIRST
OUT
LIFO
@LIFO
634
Output
Required
FIRST IN FIRST
OUT
FIFO
@FIFO
633
Output
Required
TB: 1st stack
address
N: Number of
words
SSET(630)
TB
N
m+(N-1)
m+(N
–1)
Last word
in stack
Stack
pointer
PLC memory
address
N words
in stack
TB
TB+1
TB+2
TB+3
Defines a stack of the specified length beginning at the specified word and
initializes the words in the data region to all zeroes.
TB: 1st stack
address
S: Source word
PUSH(632)
TB
S
PLC memory
address
PUSH(632)
PLC memory
address
TB
TB+1
TB+2
TB+3
TB
TB+1
TB+2
TB+3
Writes one word of data to the specified stack.
TB: 1st stack
address
D: Destination
word
LIFO(634)
TB
D
TB
TB+1
TB+2
TB+3
TB
TB+1
TB+2
TB+3
m–1
m–1
m–1
PLC memory
address
Newest
data
PLC memory
address
Last-in first-out
Stack
pointer
Stack
pointer
A is
left un-
chang-
ed.
The pointer is
decremented.
Reads the last word of data written to the specified stack (the newest data in the
stack).
TB: 1st stack
address
D: Destination
word
FIFO(633)
TB
D
m–1
m–1
PLC memory
address
Oldest
data
PLC memory
address
First-in first-out
Stack
pointer
Stack
pointer
TB
TB+1
TB+2
TB+3
TB
TB+1
TB+2
TB+3
Reads the first word of data written to the specified stack (the oldest data in the
stack).