Return from Subroutine
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
| \(PC_l \longleftarrow (SP) \\ PC_h \longleftarrow (SP+1) \\ SP \longleftarrow SP+2\) | |||||||
| RET | |||||||
| 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 |
| \(\begin{rcases} PC_l \longleftarrow (SP) \\ PC_h \longleftarrow (SP+1) \\ SP \longleftarrow SP+2 \end{rcases} \text{ if } ccc = true\) | |||||||
| RET ccc | |||||||
| 1 | 1 | ccc | 0 | 0 | 0 | ||
| ccc | Abbrev | Condition | Flag |
|---|---|---|---|
| 000 | NZ | Non Zero | Z |
| 001 | Z | Zero | |
| 010 | NC | No Carry | C |
| 011 | C | Carry | |
| 100 | PO | Parity Odd | P/V |
| 101 | PE | Parity Even | |
| 110 | P | Sign Positive | S |
| 111 | M | Sign Negative |
Timing
The unconditional RET takes 10 (4,3,3) T-States. The conditional RET takes 17(5,3,3) T-States if the condition is true and 5 T-States if false and no return was performed.
Flags Affected
| None. |
Opcode Matrix
| Uncond | C | NC | Z | NZ | PE | PO | N | P | |
|---|---|---|---|---|---|---|---|---|---|
| RET |
RET
C9110 |
RET C
D8111 |
RET NC
D0111 |
RET Z
C8111 |
RET NZ
C0111 |
RET PE
E8111 |
RET PO
E0111 |
RET N
F8111 |
RET P
F0111 |
|
Instruction
Opcode hexSize bytesCycle count
| Flow |
Last modified November 16, 2021: Add flags to jp, jr, djnz & call operations (ae1613e)