Texas Instruments MSC1210 - Manual (Page 305)

8052 Instruction Set
E-21
8052 Instruction Set
RET Return from Subroutine
Syntax RET
Instructions OpCode Bytes Cycles Flags
RET 0x22 1 2 None
RET is used to return from a subroutine previously called by LCALL or ACALL.
Program execution continues at the address that is calculated by POPping the
top-most two bytes off the stack. The most-significant byte is POPped off the
stack first, followed by the least-significant byte.
See also: LCALL, ACALL, RETI
RETI Return from Interrupt
Syntax RETI
Instructions OpCode Bytes Cycles Flags
RETI 0x32 1 2 None
RETI is used to return from an interrupt service routine. RETI first enables in-
terrupts of equal and lower priorities to the interrupt that is terminating. Pro-
gram execution continues at the address that is calculated by POPping the
top−most 2 bytes off the stack. The most-significant byte is POPped off the
stack first, followed by the least-significant byte.
RETI functions identically to RET if it is executed outside of an interrupt service
routine.
See also: RET
RL Rotate Accumulator Left
Syntax RL A
Instructions OpCode Bytes Cycles Flags
RL A 0x23 1 1 C
RL shifts the bits of the accumulator to the left. The left-most bit (bit 7) of the
accumulator is loaded into bit 0.
See also: RLC, RR, RRC