Texas Instruments TMS320C2XX User Manual
Page 288
Pop Top of Stack to Low Accumulator
POP
7-135
Assembly Language Instructions
Syntax
POP
Operands
None
Opcode
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
1
0
0
1
1
0
0
0
1
1
1
1
1
0
1
Execution
Increment PC, then ...
(TOS)
→
ACC(15:0)
0
→
ACC(31:16)
Pop stack one level
Status Bits
None
Description
The content of the top of the stack (TOS) is copied to the low accumulator, and
then the stack values move up one level. The upper half of the accumulator
is set to all zeros.
The hardware stack functions as a last-in, first-out stack with eight locations.
Any time a pop occurs, every stack value is copied to the next higher stack lo-
cation, and the top value is removed from the stack. After a pop, the bottom
two stack words will have the same value. Because each stack value is copied,
if more than seven stack pops (using the POP, POPD, RETC, or RET instruc-
tions) occur before any pushes occur, all levels of the stack will contain the
same value. No provision exists to check stack underflow.
Words
1
Cycles for a Single POP Instruction
ROM
DARAM
SARAM
External
1
1
1
1+p
Cycles for a Repeat (RPT) Execution of a POP Instruction
ROM
DARAM
SARAM
External
n
n
n
n+p
Cycles