S3F80P5_UM_ REV1.00 INSTRUCTION SET
POP — Pop From Stack
POP dst
Operation: dst ← @SP
SP ← SP + 1
The contents of the location addressed by the stack pointer are loaded into the destination. The
stack pointer is then incremented by one.
Flags: No flags affected.
Format:
Bytes Cycles Opcode
(Hex) Addr Mode
dst
opc dst 2 8 50 R
8 51 IR
Examples: Given: Register 00H = 01H, register 01H = 1BH, SPH (0D8H) = 00H, SPL (0D9H) = 0FBH,
and stack register 0FBH = 55H:
POP 00H → Register 00H = 55H, SP = 00FCH
POP @00H → Register 00H = 01H, register 01H = 55H, SP = 00FCH
In the first example, general register 00H contains the value 01H. The statement "POP 00H"
loads the contents of location 00FBH (55H) into destination register 00H and then increments the
stack pointer by one. Register 00H then contains the value 55H and the SP points to location
00FCH.
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