714
Table Data Processing Instructions Section 3-17
Description LIFO(634) reads the data from the address indicated by the stack pointer (the
newest word of data in the stack), decrements the stack pointer by one, and
outputs the data to D. The word that was read is left unchanged.
Use LIFO(634) in combination with PUSH(632). After PUSH(632) has been
used to write data into a stack, LIFO(634) can be used to read data from the
stack on a last-in first-out basis. After data is stored by PUSH(632), the stack
pointer indicates the address next to the last data.
Flags
Precautions The stack must be defined in advance with SSET(630).
Index Registers ---
Indirect addressing
using Index Registers
,IR0 to ,IR15
–2048 to +2047 ,IR0 to –2048 to +2047 ,IR15
DR0 to DR15, IR0 to IR15
,IR0+(++) to ,IR15+(++)
,–(– –)IR0 to, –(– –)IR15
Area TB D
TB
TB+1
TB+2
TB+3
TB
TB+1
TB+2
TB+3
m–1 m–1
m–1
Reading
A is left unchanged.
Stack
pointer
PC memory
address
PC memory
address
Newest
data
Stack
pointer
The pointer is
decremented.
Name Label Operation
Error Flag ER ON if the contents of the stack pointer (TB+3 and TB+2) is
less than or equal to the PLC memory address of first
word in the data region of the stack (TB+4).
(This is a stack underflow error.)
OFF in all other cases.