Z-80 Instructions: Part C.

EXCHANGE GROUP AND BLOCK TRANSFER AND SEARCH GROUP

Mnemonic		 Symbolic
Operation		 Flags OP-Code No. of
Bytes		 No. of
M Cycles		 No. of
T Cycles
Comments
C Z P/V S N H 76 543 210
EX DE,HL DE ↔ HL '  • • • • • • 01 101 011 1 1 4  
EX AF,AF' AF ↔ AF' • • • • • • 00 001 000 1 1 4  
EXX BC ↔ BC '
DE ↔ DE '
HL ↔ HL '		 • • • • • • 11 011 001 1 1 4 Register bank and
auxiliary register
bank exchange
EX (SP),HL H ↔ (SP+1)
L ↔ (SP)		 • • • • • • 11 100 011 1 5 19  
EX (SP),IX IXH ↔ (SP+1)
IXL ↔ (SP)		 • • • • • • 11 011 101
11 100 011		 2 6 23  
EX (SP),IY IYH ↔ (SP+1)
IYL ↔ (SP)		 • • • • • • 11 111 101
11 100 011		 2 6 23  
LDI (DE) ← (HL)
DE ← DE + 1
HL ← HL + 1
BC ← BC - 1		 • • ①
↕		 • 0 0 11 101 101
10 100 000		 2 4 16 Load (HL) into (DE),
increment the pointers and
decrement the byte
counter (BC)
LDIR (DE) ← (HL)
DE ← DE + 1
HL ← HL + 1
BC ← BC - 1
Repeat until
BC = 0		 • • 0 • 0 0 11 101 101
10 110 000		 2
2		 5
4		 21
16		 If BC ≠ 0
If BC = 0
LDD (DE) ← (HL)
DE ← DE - 1
HL ← HL - 1
BC ← BC - 1		 • • ①
↕		 • 0 0 11 101 101
10 101 000		 2 4 16  
LDDR (DE) ← (HL)
DE ← DE - 1
HL ← HL - 1
BC ← BC - 1
Repeat until
BC = 0		 • • 0 • 0 0 11 101 101
10 111 000		 2
2		 5
4		 21
16		 If BC ≠ 0
If BC = 0
CPI A - (HL)
DE ← DE + 1
HL ← HL + 1
BC ← BC - 1		 • ②
↕		 ①
↕		 ↕ 1 ↕ 11 101 101
10 100 001		 2 4 16  
CPIR A - (HL)
DE ← DE + 1
HL ← HL + 1
BC ← BC - 1
Repeat until
A = (HL) or
BC = 0		 • ②
↕		 ①
↕		 ↕ 1 ↕ 11 101 101
10 110 001		 2
 
2		 5
 
4		 21
 
16		 If BC ≠ 0 and
    A ≠ (HL)
If BC = 0 or
    A = (HL)
CPD A - (HL)
DE ← DE - 1
HL ← HL - 1
BC ← BC - 1		 • ②
↕		 ①
↕		 ↕ 1 ↕ 11 101 101
10 101 001		 2 4 16  
CPDR (DE) ← (HL)
DE ← DE - 1
HL ← HL - 1
BC ← BC - 1
Repeat until
A = (HL) or
BC = 0		 • ②
↕		 ①
↕		 ↕ 1 ↕ 11 101 101
10 111 001		 2
 
2		 5
 
4		 21
 
16		 If BC ≠ 0 and
      A ≠ (HL)
If BC = 0 or
      A = (HL)

 Notes:   ①  P/V flag is 0 if the result of BC-1 = 0, otherwise P/V =1
   ②  Z flag is 1 if A = (HL), otherwise Z = 0
 
 Flag Notation:   • = flag not affected, 0 = flag reset, 1 = flag set, X = flag is unknown, 
   ↕ = flag is affected according to the result of the operation.