S3C828B Datasheet, PDF (213/369 Pages) Samsung semiconductor – 8-BIT CMOS MICROCONTROLLERS

INSTRUCTION SET
S3C828B/F828B/C8289/F8289/C8285/F8285
RET — Return
RET
Operation:
Flags:
PC ← @SP
SP ← SP + 2
The RET instruction is normally used to return to the previously executing procedure at the end of
a procedure entered by a CALL instruction. The contents of the 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.
No flags are affected.
Format:
opc
Bytes
1
Cycles
8 (internal stack)
10 (internal stack)
Opcode (Hex)
AF
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 the program counter. The stack pointer then pops the value in location 00FEH (1AH) into the
PC's low byte and the instruction at location 101AH is executed. The stack pointer now points to
memory location 00FEH.
6-70