qqH <- (SP+1), qqL <- (SP)
POP
| b7 | b6 | b5 | b4 | b3 | b2 | b1 | b0 |
|---|---|---|---|---|---|---|---|
| 1 | 1 | 0 | 0 | 0 | 1 | ||
The top two bytes of the external memory last-in, first-out (LIFO) stack are popped to register pair qq. The Stack Pointer (SP) Register pair holds the 16-bit address of the current top of the Stack. This instruction first loads to the low-order portion of qq, the byte at the memory location corresponding to the contents of SP; then SP is incremented and the con- tents of the corresponding adjacent memory location are loaded to the high-order portion of qq and the SP is now incremented again. The operand qq identifies register pair BC, DE, HL, or AF, assembled as follows in the object code:
| Register | dd | Hex |
|---|---|---|
| BC | 00 | $C1 |
| DE | 01 | $D1 |
| HL | 10 | $E1 |
| AF | 11 | $F1 |
None
If the Stack Pointer contains $1000, memory location $1000 contains $55 and location $1001 contains $33, the instruction
POP HL
results in register pair HL containing $3355 and the Stack Pointer containing $1002.