Little- and big-endian memory organizations
bit 0
bit 31
bit 0
bit 31
23
22
21
20
20
21
22
23
19
18
17
16
16
17
18
19
word16
word16
14
15
13
12
12
10
11
9
8
8
6
5
4
byt e6 half -word4
2
3
1
byt e
address
0
byt e3 byt e2 byt e1 byt e0
(a) Litt le-endian memory
organizat ion
©2000 Addison Wesley
14
15
9
10
11
word8
word8
7
13
half -word12 half -word14
half -word14 half -word12
4
5
6
7
byt e5 half -word6
0
1
2
byt e
address
3
byt e0 byt e1 byt e2 byt e3
(b) Big-endian memory
organizat ion
ARM operating modes and register usage.
CPS R[ 4 : 0 ]
10000
10001
10010
10011
10111
11011
11111
©2000 Addison Wesley
Mo de
User
FIQ
IRQ
SVC
Abort
Undef
System
Us e
Normal user code
Processing fast interrupts
Processing standard interrupts
Processing software interrupts (SWIs)
Processing memory faults
Handling undefined instruction traps
Running privileged operating system tasks
Re g i s t e rs
user
_fiq
_irq
_svc
_abt
_und
user
Exception vector addresses
Ex c e p t i o n
Reset
Undefined instruction
Software interrupt (SWI)
Prefetch abort (instruction fetch memory fault)
Data abort (data access memory fault)
IRQ (normal interrupt)
FIQ (fast interrupt)
©2000 Addison Wesley
Mo de
SVC
UND
SVC
Abort
Abort
IRQ
FIQ
Ve c t o r addre s s
0x00000000
0x00000004
0x00000008
0x0000000C
0x00000010
0x00000018
0x0000001C
The ARM condition code field
31
28 27
cond
©2000 Addison Wesley
0
ARM condition codes
Op c o de
[3 1 :2 8 ]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Mn e mo n i c
ex tens i o n
EQ
NE
CS/HS
CC/LO
MI
PL
VS
VC
HI
LS
GE
LT
GT
LE
AL
NV
©2000 Addison Wesley
In t e rp re t at i o n
Equal / equals zero
Not equal
Carry set / unsigned higher or same
Carry clear / unsigned lower
Minus / negative
Plus / positive or zero
Overflow
No overflow
Unsigned higher
Unsigned lower or same
Signed greater than or equal
Signed less than
Signed greater than
Signed less than or equal
Always
Never (do not use!)
S t at us f l ag s t at e f o r
e x e c ut i o n
Z set
Z clear
C set
C clear
N set
N clear
V set
V clear
C set and Z clear
C clear or Z set
N equals V
N is not equal to V
Z clear and N equals V
Z set or N is not equal to V
any
none
Branch and Branch with Link binary encoding
31
28 27
cond
©2000 Addison Wesley
25 2423
101 L
0
24-bit signed word of f set
Branch (with optional link) and exchange instruction
binary encoding
(1) BX|BLX Rm
31
2827
6 5 4 3
0001001011111111111100
cond
L 1
0
Rm
(2) BLX label
31
2827
2524 23
1111 101 H
©2000 Addison Wesley
0
24-bit signed word offset
Software interrupt binary encoding
31
28 27
cond
©2000 Addison Wesley
2423
1111
0
24-bit (interpret ed) immediat e
Data processing instruction binary encoding
31
28 2726 25 24
cond
21 20 19
0 0 # opcode S
1615
Rn
12 11
0
operand 2
Rd
destination register
first operand register
set condition codes
arithmetic/logic function
25
11
8 7
#rot
1
0
8-bit immediate
immediate alignment
11
7 6 5 4 3
#shift
25
immediate shift length
0
shift type
Sh 0
0
Rm
second operand register
11
8 7 6 5 4 3
Rs
register shift length
©2000 Addison Wesley
0 Sh 1
0
Rm
ARM data processing instructions
Op c o de
[2 4 :2 1 ]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Mn e mo n i c
Me an i n g
Ef f e c t
AND
EOR
SUB
RSB
ADD
ADC
SBC
RSC
TST
TEQ
CMP
CMN
ORR
MOV
BIC
MVN
Logical bit-wise AND
Logical bit-wise exclusive OR
Subtract
Reverse subtract
Add
Add with carry
Subtract with carry
Reverse subtract with carry
Test
Test equivalence
Compare
Compare negated
Logical bit-wise OR
Move
Bit clear
Move negated
Rd := Rn AND Op2
Rd := Rn EOR Op2
Rd := Rn - Op2
Rd := Op2 - Rn
Rd := Rn + Op2
Rd := Rn + Op2 + C
Rd := Rn - Op2 + C - 1
Rd := Op2 - Rn + C - 1
Scc on Rn AND Op2
Scc on Rn EOR Op2
Scc on Rn - Op2
Scc on Rn + Op2
Rd := Rn OR Op2
Rd := Op2
Rd := Rn AND NOT Op2
Rd := NOT Op2
©2000 Addison Wesley
Multiply instruction binary encoding
31
28 27
cond
©2000 Addison Wesley
2423
0000
21 20 19
1615
12 11
mul S Rd/RdHi Rn/RdLo
8 7
Rs
4 3
1001
0
Rm
Multiply instructions
Op c o de
[2 3 :2 1 ]
000
001
100
101
110
111
Mn e mo n i c
Me an i n g
Ef f e c t
MUL
MLA
UMULL
UMLAL
SMULL
SMLAL
Multiply (32-bit result)
Multiply-accumulate (32-bit result)
Unsigned multiply long
Unsigned multiply-accumulate long
Signed multiply long
Signed multiply-accumulate long
Rd := (Rm * Rs) [31:0]
Rd := (Rm * Rs + Rn) [31:0]
RdHi:RdLo := Rm * Rs
RdHi:RdLo += Rm * Rs
RdHi:RdLo := Rm * Rs
RdHi:RdLo += Rm * Rs
©2000 Addison Wesley
Count leading zeros instruction binary encoding
31
28 27
cond
16 15
0 001 011 000 00
destination register
©2000 Addison Wesley
12 11
Rd
4 3
00 000 001
0
Rm
source register
Single word and unsigned byte data transfer
instruction binary encoding
31
28 2726 25 2423 2221 20 19
cond
0 1 # P U BW L
1615
Rn
12 11
0
of f set
Rd
source/desti nation reg ister
base r eg ister
load/store
write- back (auto- index)
unsig ned byte/word
up/down
pre- /post-i ndex
25
11
12-bit immediat e
0
25
11
7 6 5 4 3
#shif t
1
immediate shift leng th
shift type
offset reg ister
©2000 Addison Wesley
0
Sh 0
0
Rm
Half-word and signed byte data transfer instruction
binary encoding
31
28 27
cond
25 2423 2221 20 19
000 PU#WL
1615
Rn
12 11
Rd
8 7 6 5 4 3
0
of f set H 1 S H 1 of f set L
source/desti nation reg ister
base r eg ister
load/store
write- back (auto- index)
up/down
pre- /post-i ndex
22
11
1
Imm [7:4]
Imm [3:0]
22
11
3
8
0000
0
offset reg ister
©2000 Addison Wesley
8
3
0
0
Rm
Data type encoding
S
1
0
1
©2000 Addison Wesley
H
0
1
1
Dat a t y p e
Signed byte
Unsigned half-word
Signed half-word
Multiple register data transfer instruction binary
encoding
31
28 27
cond
25 2423 2221 20 19
1 0 0 P U SW L
1615
Rn
0
register list
base r eg ister
load/store
write- back (auto- index)
restor e PSR and force user bi t
up/down
pre- /post-i ndex
©2000 Addison Wesley
Swap memory and register instruction binary
encoding
31
28 27
cond
23 2221 20 19
00010 B 00
1615
Rn
12 11
Rd
4 3
0000100 1
0
Rm
destination r eg ister
base r eg ister
unsig ned byte/word
©2000 Addison Wesley
source r eg ister
Status register to general register transfer instruction
binary encoding
31
28 27
cond
23 2221
1615
00010 R 001111
12 11
Rd
0
0000000 00000
destination r eg ister
SPSR/CPSR
©2000 Addison Wesley
Transfer to status register instruction binary
encoding
31
28 27 26 25 24 23 22 21 20 19
cond
00 # 10 R 10
16 15
field
12 11
0
operand
1111
field mask
SPSR/CPSR
25
11
1
8 7
#rot
0
8-bit immediate
immediate alignment
25
11
0
00000000
operand register
©2000 Addison Wesley
4 3
0
Rm
Coprocessor data processing instruction binary
encoding
31
28 27
cond
©2000 Addison Wesley
2423
1110
20 19
Cop1
1615
CRn
12 11
CRd
8 7
CP#
5 4 3
Cop2 0
0
CRm
Coprocessor data transfer instruction binary
encoding
31
28 27
cond
25 2423 2221 20 19
1 1 0 P U NW L
1615
Rn
12 11
CRd
8 7
CP#
0
8-bit of f set
source/desti nation reg ister
base r eg ister
load/store
write- back (auto- index)
data size ( copr ocessor dependent)
up/down
pre- /post-i ndex
©2000 Addison Wesley
Coprocessor register transfer instruction binary
encoding
31
28 27
cond
2423
21 20 19
1 1 1 0 Cop1 L
1615
CRn
12 11
Rd
8 7
CP#
5 4 3
Cop2 1
0
CRm
load from coprocessor/store to coprocessor
©2000 Addison Wesley
Breakpoint instruction binary encoding
31
28 27
111 0
©2000 Addison Wesley
20 19
00 010 010
16 15
xxxx
12 11
x xx x
8 7
xxxx
4 3
01 11
0
xxxx
Arithmetic instruction extension space
31
28 27
cond
©2000 Addison Wesley
2221 20 19
000001
op
1615
Rn
12 11
Rd
8 7
Rs
4 3
1001
0
Rm
Control instruction extension space
31
28 27
23 2221 20 19
1615
12 11
8 7 6
c ond
0 0 0 1 0 op1 0
Rn
Rd
Rs
c ond
0 0 0 1 0 op1 0
Rn
Rd
Rs
c ond
0 0 1 1 0 op1 0
Rn
Rd
#rot
©2000 Addison Wesley
op2
4 3
0
0
Rm
0 op2 1
Rm
8-bit immediate
Data transfer instruction extension space
31
28 27
cond
©2000 Addison Wesley
25 2423 2221 20 19
0 0 0 P U BW L
1615
Rn
12 11
Rd
8 7 6 5 4 3
Rs
1 op1 1
0
Rm
Coprocessor instruction extension space
31
28 27
cond
©2000 Addison Wesley
25 2423 2221 20 19
1 1 0 0 op 0 X
1615
Rn
12 11
CRd
8 7
CP#
0
of f set
Undefined instruction space
31
28 27
cond
©2000 Addison Wesley
25 24
011
5 4 3
XXXXXXX XXXXXXXXXXXX X
0
1 XXXX
Summary of ARM architectures
Core
Architecture
ARM1
v1
ARM2
v2
ARM2as, ARM3
v2a
ARM6, ARM600, ARM610
v3
ARM7, ARM700, ARM710
v3
ARM7TDMI, ARM710T, ARM720T, ARM740T
v4T
StrongARM, ARM8, ARM810
v4
ARM9TDMI, ARM920T, ARM940T
v4T
ARM9ES
v5TE
ARM10TDMI, ARM1020E
v5TE
©2000 Addison Wesley