429
8025I–AVR–02/09
ATmega48P/88P/168P/328P
29. Instruction Set Summary
Mnemonics
Operands
Description
Operation
Flags
#Clocks
ARITHMETIC AND LOGIC INSTRUCTIONS
ADD
Rd, Rr
Add two Registers
Rd
←
Rd + Rr
Z,C,N,V,H
1
ADC
Rd, Rr
Add with Carry two Registers
Rd
←
Rd + Rr + C
Z,C,N,V,H
1
ADIW
Rdl,K
Add Immediate to Word
Rdh:Rdl
←
Rdh:Rdl + K
Z,C,N,V,S
2
SUB
Rd, Rr
Subtract two Registers
Rd
←
Rd - Rr
Z,C,N,V,H
1
SUBI
Rd, K
Subtract Constant from Register
Rd
←
Rd - K
Z,C,N,V,H
1
SBC
Rd, Rr
Subtract with Carry two Registers
Rd
←
Rd - Rr - C
Z,C,N,V,H
1
SBCI
Rd, K
Subtract with Carry Constant from Reg.
Rd
←
Rd - K - C
Z,C,N,V,H
1
SBIW
Rdl,K
Subtract Immediate from Word
Rdh:Rdl
←
Rdh:Rdl - K
Z,C,N,V,S
2
AND
Rd, Rr
Logical AND Registers
Rd
←
Rd
•
Rr
Z,N,V
1
ANDI
Rd, K
Logical AND Register and Constant
Rd
←
Rd
•
K
Z,N,V
1
OR
Rd, Rr
Logical OR Registers
Rd
←
Rd v Rr
Z,N,V
1
ORI
Rd, K
Logical OR Register and Constant
Rd
←
Rd v K
Z,N,V
1
EOR
Rd, Rr
Exclusive OR Registers
Rd
←
Rd
⊕
Rr
Z,N,V
1
COM
Rd
One’s Complement
Rd
←
0xFF
−
Rd
Z,C,N,V
1
NEG
Rd
Two’s Complement
Rd
←
0x00
−
Rd
Z,C,N,V,H
1
SBR
Rd,K
Set Bit(s) in Register
Rd
←
Rd v K
Z,N,V
1
CBR
Rd,K
Clear Bit(s) in Register
Rd
←
Rd
•
(0xFF - K)
Z,N,V
1
INC
Rd
Increment
Rd
←
Rd + 1
Z,N,V
1
DEC
Rd
Decrement
Rd
←
Rd
−
1
Z,N,V
1
TST
Rd
Test for Zero or Minus
Rd
←
Rd
•
Rd
Z,N,V
1
CLR
Rd
Clear Register
Rd
←
Rd
⊕
Rd
Z,N,V
1
SER
Rd
Set Register
Rd
←
0xFF
None
1
MUL
Rd, Rr
Multiply Unsigned
R1:R0
←
Rd x Rr
Z,C
2
MULS
Rd, Rr
Multiply Signed
R1:R0
←
Rd x Rr
Z,C
2
MULSU
Rd, Rr
Multiply Signed with Unsigned
R1:R0
←
Rd x Rr
Z,C
2
FMUL
Rd, Rr
Fractional Multiply Unsigned
R1:R0
←
(Rd x Rr)
<< 1
Z,C
2
FMULS
Rd, Rr
Fractional Multiply Signed
R1:R0
←
(Rd x Rr)
<< 1
Z,C
2
FMULSU
Rd, Rr
Fractional Multiply Signed with Unsigned
R1:R0
←
(Rd x Rr)
<< 1
Z,C
2
BRANCH INSTRUCTIONS
RJMP
k
Relative Jump
PC
←
PC + k + 1
None
2
IJMP
Indirect Jump to (Z)
PC
←
Z
None
2
k
Direct Jump
PC
←
k
None
3
RCALL
k
Relative Subroutine Call
PC
←
PC + k + 1
None
3
ICALL
Indirect Call to (Z)
PC
←
Z
None
3
CALL
k
Direct Subroutine Call
PC
←
k
None
4
RET
Subroutine Return
PC
←
STACK
None
4
RETI
Interrupt Return
PC
←
STACK
I
4
CPSE
Rd,Rr
Compare, Skip if Equal
if (Rd = Rr) PC
←
PC + 2 or 3
None
1/2/3
CP
Rd,Rr
Compare
Rd
−
Rr
Z, N,V,C,H
1
CPC
Rd,Rr
Compare with Carry
Rd
−
Rr
−
C
Z, N,V,C,H
1
CPI
Rd,K
Compare Register with Immediate
Rd
−
K
Z, N,V,C,H
1
SBRC
Rr, b
Skip if Bit in Register Cleared
if (Rr(b)=0) PC
←
PC + 2 or 3
None
1/2/3
SBRS
Rr, b
Skip if Bit in Register is Set
if (Rr(b)=1) PC
←
PC + 2 or 3
None
1/2/3
SBIC
P, b
Skip if Bit in I/O Register Cleared
if (P(b)=0) PC
←
PC + 2 or 3
None
1/2/3
SBIS
P, b
Skip if Bit in I/O Register is Set
if (P(b)=1) PC
←
PC + 2 or 3
None
1/2/3
BRBS
s, k
Branch if Status Flag Set
if (SREG(s) = 1) then PC
←
PC+k + 1
None
1/2
BRBC
s, k
Branch if Status Flag Cleared
if (SREG(s) = 0) then PC
←
PC+k + 1
None
1/2
BREQ
k
Branch if Equal
if (Z = 1) then PC
←
PC + k + 1
None
1/2
BRNE
k
Branch if Not Equal
if (Z = 0) then PC
←
PC + k + 1
None
1/2
BRCS
k
Branch if Carry Set
if (C = 1) then PC
←
PC + k + 1
None
1/2
BRCC
k
Branch if Carry Cleared
if (C = 0) then PC
←
PC + k + 1
None
1/2
BRSH
k
Branch if Same or Higher
if (C = 0) then PC
←
PC + k + 1
None
1/2
BRLO
k
Branch if Lower
if (C = 1) then PC
←
PC + k + 1
None
1/2
BRMI
k
Branch if Minus
if (N = 1) then PC
←
PC + k + 1
None
1/2
BRPL
k
Branch if Plus
if (N = 0) then PC
←
PC + k + 1
None
1/2
BRGE
k
Branch if Greater or Equal, Signed
if (N
⊕
V= 0) then PC
←
PC + k + 1
None
1/2
BRLT
k
Branch if Less Than Zero, Signed
if (N
⊕
V= 1) then PC
←
PC + k + 1
None
1/2
BRHS
k
Branch if Half Carry Flag Set
if (H = 1) then PC
←
PC + k + 1
None
1/2
BRHC
k
Branch if Half Carry Flag Cleared
if (H = 0) then PC
←
PC + k + 1
None
1/2
BRTS
k
Branch if T Flag Set
if (T = 1) then PC
←
PC + k + 1
None
1/2
BRTC
k
Branch if T Flag Cleared
if (T = 0) then PC
←
PC + k + 1
None
1/2
BRVS
k
Branch if Overflow Flag is Set
if (V = 1) then PC
←
PC + k + 1
None
1/2
BRVC
k
Branch if Overflow Flag is Cleared
if (V = 0) then PC
←
PC + k + 1
None
1/2