S3F84B8_UM_REV 1.00 6 INSTRUCTION SET
6-69
6.3.56 RET — RETURN
RET
Opera
tion: PC @SP
SP SP + 2
Typically, the RET instruction is used to return to the previously executed procedure at the end of
a procedure entered by a CALL instruction. The contents of location addressed by the stack
pointer are popped into the program counter. The next statement that is executed is the one that
is addressed by the new program counter value.
Flags: No flags are affected.
Format:
Bytes Cycles Opcode (Hex)
opc 1 8 (internal stack) AF
10 (internal stack)
Example: Given SP = 00FCH, (SP) = 101AH, and PC = 1234:
RET PC = 101AH, SP = 00FEH
The statement “RET” pops the contents of stack pointer location 00FCH (10H) into the high byte
of program counter. The stack pointer then pops the value in location 00FEH (1AH) to the PC’s
low byte and the instruction at location 101AH is executed. The stack pointer now points to
memory location 00FEH.
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