Texas Instruments MSC1210 - Manual (Page 304)

8052 Instruction Set
E-20
POP Pop Value from Stack
Syntax POP register
Instructions OpCode Bytes Cycles Flags
POP direct 0xD0 2 2 None
POP pops the last value placed on the stack into the direct address specified. In
other words, POP will load direct with the value of the internal RAM address pointed
to by the current stack pointer. The stack pointer is then decremented by 1.
Note:
The address of direct must be an internal RAM or SFR address. You cannot
POP directly into R registers such as R0, R1, etc.. For example, to POP a
value off the stack into R0, POP the value into the accumulator and then
move the value of the accumulator into R0.
Note:
When POPping a value off the stack into the accumulator, code the instruc-
tion as POP ACC, not POP A. The latter is invalid and will result in an error
at assemble time.
See also: PUSH
PUSH Push Value onto Stack
Syntax PUSH register
Instructions OpCode Bytes Cycles Flags
PUSH direct 0xC0 2 2 None
PUSH pushes the value of the specified direct address onto the stack. PUSH
first increments the value of the stack pointer by 1, then takes the value stored
in direct and stores it in internal RAM at the location pointed to by the increm-
ented stack pointer.
Note:
The address of direct must be an internal RAM or SFR address. You cannot
PUSH directly from R registers such as R0, R1, etc. For example, to push
a value onto the stack from R0, move R0 into the accumulator, and then
PUSH the value of the accumulator onto the stack.
Note:
When PUSHing a value from the accumulator onto the stack into the, code
the instruction as PUSH ACC, not PUSH A. The latter is invalid and will result
in an error at assemble time.
See also: POP