Texas Instruments MSC1210 manual Pop Value from Stack, Push Value onto Stack

8052 Instruction Set

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

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