Pop qq – Zilog Z08470 User Manual
Page 129
UM008007-0715
Z80 Instruction Description
Z80 CPU
User Manual
117
POP qq
Operation
qqH ← (SP+1), qqL ← (SP)
Op Code
POP
Operand
Description
The top two bytes of the external memory last-in, first-out (LIFO) stack are popped to reg-
ister 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:
Condition Bits Affected
None.
Pair
r
BC
00
DE
01
HL
10
AF
11
M Cycles
T States
4 MHz E.T.
3
10 (4, 3, 3)
2.50
1
1
q
0
1
0
q
0