Samsung P8245 Microscope & Magnifier User Manual


 
S3C8245/P8245/C8249/P8249 INSTRUCTION SET
6-71
RET Return
RET
Operation: 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.
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
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.