One goal of the RISC-V project is that it be used as a stable software
development target. For this purpose, we define a combination of a base
ISA (RV32I or RV64I) plus selected standard extensions (IMAFD, Zicsr,
Zifencei) as a "general-purpose" ISA, and we use the abbreviation G
for the IMAFDZicsr_Zifencei combination of instruction-set extensions.
This chapter presents opcode maps and instruction-set listings for RV32G
and RV64G.
Table 1. RISC-V base opcode map, inst[1:0]=11
inst[4:2]
|
000
|
001
|
010
|
011
|
100
|
101
|
110
|
111 (>32b) |
inst[6:5]
|
00
|
LOAD
|
LOAD-FP
|
custom-0
|
MISC-MEM
|
OP-IMM
|
AUIPC
|
OP-IMM-32
|
48b |
01
|
STORE
|
STORE-FP
|
custom-1
|
AMO
|
OP
|
LUI
|
OP-32
|
64b |
10
|
MADD
|
MSUB
|
NMSUB
|
NMADD
|
OP-FP
|
OP-V
|
custom-2/rv128
|
48b |
11
|
BRANCH
|
JALR
|
reserved
|
JAL
|
SYSTEM
|
reserved
|
custom-3/rv128
|
≥80b |
Table 1 shows a map of the major opcodes for
RVG. Major opcodes with 3 or more lower bits set are reserved for
instruction lengths greater than 32 bits. Opcodes marked as reserved
should be avoided for custom instruction-set extensions as they might be
used by future standard extensions. Major opcodes marked as custom-0
and custom-1 will be avoided by future standard extensions and are
recommended for use by custom instruction-set extensions within the base
32-bit instruction format. The opcodes marked custom-2/rv128 and
custom-3/rv128 are reserved for future use by RV128, but will
otherwise be avoided for standard extensions and so can also be used for
custom instruction-set extensions in RV32 and RV64.
We believe RV32G and RV64G provide simple but complete instruction sets
for a broad range of general-purpose computing. The optional compressed
instruction set described in [compressed] can
be added (forming RV32GC and RV64GC) to improve performance, code size,
and energy efficiency, though with some additional hardware complexity.
As we move beyond IMAFDC into further instruction-set extensions, the
added instructions tend to be more domain-specific and only provide
benefits to a restricted class of applications, e.g., for multimedia or
security. Unlike most commercial ISAs, the RISC-V ISA design clearly
separates the base ISA and broadly applicable standard extensions from
these more specialized additions. [extending]
has a more extensive discussion of ways to add extensions to the RISC-V
ISA.
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
imm[11:0]
|
rs1
|
funct3
|
rd
|
opcode
|
I-type
|
imm[11:5]
|
rs2
|
rs1
|
funct3
|
imm[4:0]
|
opcode
|
S-type
|
imm[12|10:5]
|
rs2
|
rs1
|
funct3
|
imm[4:1|11]
|
opcode
|
B-type
|
imm[31:12]
|
rd
|
opcode
|
U-type
|
imm[20|10:1|11|19:12]
|
rd
|
opcode
|
J-type
|
RV32I Base Instruction Set
|
imm[31:12]
|
rd
|
0110111
|
LUI
|
imm[31:12]
|
rd
|
0010111
|
AUIPC
|
imm[20|10:1|11|19:12]
|
rd
|
1101111
|
JAL
|
imm[11:0]
|
rs1
|
000
|
rd
|
1100111
|
JALR
|
imm[12|10:5]
|
rs2
|
rs1
|
000
|
imm[4:1|11]
|
1100011
|
BEQ
|
imm[12|10:5]
|
rs2
|
rs1
|
001
|
imm[4:1|11]
|
1100011
|
BNE
|
imm[12|10:5]
|
rs2
|
rs1
|
100
|
imm[4:1|11]
|
1100011
|
BLT
|
imm[12|10:5]
|
rs2
|
rs1
|
101
|
imm[4:1|11]
|
1100011
|
BGE
|
imm[12|10:5]
|
rs2
|
rs1
|
110
|
imm[4:1|11]
|
1100011
|
BLTU
|
imm[12|10:5]
|
rs2
|
rs1
|
111
|
imm[4:1|11]
|
1100011
|
BGEU
|
imm[11:0]
|
rs1
|
000
|
rd
|
0000011
|
LB
|
imm[11:0]
|
rs1
|
001
|
rd
|
0000011
|
LH
|
imm[11:0]
|
rs1
|
010
|
rd
|
0000011
|
LW
|
imm[11:0]
|
rs1
|
100
|
rd
|
0000011
|
LBU
|
imm[11:0]
|
rs1
|
101
|
rd
|
0000011
|
LHU
|
imm[11:5]
|
rs2
|
rs1
|
000
|
imm[4:0]
|
0100011
|
SB
|
imm[11:5]
|
rs2
|
rs1
|
001
|
imm[4:0]
|
0100011
|
SH
|
imm[11:5]
|
rs2
|
rs1
|
010
|
imm[4:0]
|
0100011
|
SW
|
imm[11:0]
|
rs1
|
000
|
rd
|
0010011
|
ADDI
|
imm[11:0]
|
rs1
|
010
|
rd
|
0010011
|
SLTI
|
imm[11:0]
|
rs1
|
011
|
rd
|
0010011
|
SLTIU
|
imm[11:0]
|
rs1
|
100
|
rd
|
0010011
|
XORI
|
imm[11:0]
|
rs1
|
110
|
rd
|
0010011
|
ORI
|
imm[11:0]
|
rs1
|
111
|
rd
|
0010011
|
ANDI
|
0000000
|
shamt
|
rs1
|
001
|
rd
|
0010011
|
SLLI
|
0000000
|
shamt
|
rs1
|
101
|
rd
|
0010011
|
SRLI
|
0100000
|
shamt
|
rs1
|
101
|
rd
|
0010011
|
SRAI
|
0000000
|
rs2
|
rs1
|
000
|
rd
|
0110011
|
ADD
|
0100000
|
rs2
|
rs1
|
000
|
rd
|
0110011
|
SUB
|
0000000
|
rs2
|
rs1
|
001
|
rd
|
0110011
|
SLL
|
0000000
|
rs2
|
rs1
|
010
|
rd
|
0110011
|
SLT
|
0000000
|
rs2
|
rs1
|
011
|
rd
|
0110011
|
SLTU
|
0000000
|
rs2
|
rs1
|
100
|
rd
|
0110011
|
XOR
|
0000000
|
rs2
|
rs1
|
101
|
rd
|
0110011
|
SRL
|
0100000
|
rs2
|
rs1
|
101
|
rd
|
0110011
|
SRA
|
0000000
|
rs2
|
rs1
|
110
|
rd
|
0110011
|
OR
|
0000000
|
rs2
|
rs1
|
111
|
rd
|
0110011
|
AND
|
fm
|
pred
|
succ
|
rs1
|
000
|
rd
|
0001111
|
FENCE
|
1000
|
0011
|
0011
|
00000
|
000
|
00000
|
0001111
|
FENCE.TSO
|
0000
|
0001
|
0000
|
00000
|
000
|
00000
|
0001111
|
PAUSE
|
000000000000
|
00000
|
000
|
00000
|
1110011
|
ECALL
|
000000000001
|
00000
|
000
|
00000
|
1110011
|
EBREAK
|
|
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
imm[11:0]
|
rs1
|
funct3
|
rd
|
opcode
|
I-type
|
imm[11:5]
|
rs2
|
rs1
|
funct3
|
imm[4:0]
|
opcode
|
S-type
|
RV64I Base Instruction Set (in addition to RV32I)
|
imm[11:0]
|
rs1
|
110
|
rd
|
0000011
|
LWU
|
imm[11:0]
|
rs1
|
011
|
rd
|
0000011
|
LD
|
imm[11:5]
|
rs2
|
rs1
|
011
|
imm[4:0]
|
0100011
|
SD
|
000000
|
shamt
|
rs1
|
001
|
rd
|
0010011
|
SLLI
|
000000
|
shamt
|
rs1
|
101
|
rd
|
0010011
|
SRLI
|
010000
|
shamt
|
rs1
|
101
|
rd
|
0010011
|
SRAI
|
imm[11:0]
|
rs1
|
000
|
rd
|
0011011
|
ADDIW
|
0000000
|
shamt
|
rs1
|
001
|
rd
|
0011011
|
SLLIW
|
0000000
|
shamt
|
rs1
|
101
|
rd
|
0011011
|
SRLIW
|
0100000
|
shamt
|
rs1
|
101
|
rd
|
0011011
|
SRAIW
|
0000000
|
rs2
|
rs1
|
000
|
rd
|
0111011
|
ADDW
|
0100000
|
rs2
|
rs1
|
000
|
rd
|
0111011
|
SUBW
|
0000000
|
rs2
|
rs1
|
001
|
rd
|
0111011
|
SLLW
|
0000000
|
rs2
|
rs1
|
101
|
rd
|
0111011
|
SRLW
|
0100000
|
rs2
|
rs1
|
101
|
rd
|
0111011
|
SRAW
|
RV32/RV64 Zifencei Standard Extension
|
imm[11:0]
|
rs1
|
001
|
rd
|
0001111
|
FENCE.I
|
RV32/RV64 Zicsr Standard Extension
|
csr
|
rs1
|
001
|
rd
|
1110011
|
CSRRW
|
csr
|
rs1
|
010
|
rd
|
1110011
|
CSRRS
|
csr
|
rs1
|
011
|
rd
|
1110011
|
CSRRC
|
csr
|
uimm
|
101
|
rd
|
1110011
|
CSRRWI
|
csr
|
uimm
|
110
|
rd
|
1110011
|
CSRRSI
|
csr
|
uimm
|
111
|
rd
|
1110011
|
CSRRCI
|
RV32M Standard Extension
|
0000001
|
rs2
|
rs1
|
000
|
rd
|
0110011
|
MUL
|
0000001
|
rs2
|
rs1
|
001
|
rd
|
0110011
|
MULH
|
0000001
|
rs2
|
rs1
|
010
|
rd
|
0110011
|
MULHSU
|
0000001
|
rs2
|
rs1
|
011
|
rd
|
0110011
|
MULHU
|
0000001
|
rs2
|
rs1
|
100
|
rd
|
0110011
|
DIV
|
0000001
|
rs2
|
rs1
|
101
|
rd
|
0110011
|
DIVU
|
0000001
|
rs2
|
rs1
|
110
|
rd
|
0110011
|
REM
|
0000001
|
rs2
|
rs1
|
111
|
rd
|
0110011
|
REMU
|
RV64M Standard Extension (in addition to RV32M)
|
0000001
|
rs2
|
rs1
|
000
|
rd
|
0111011
|
MULW
|
0000001
|
rs2
|
rs1
|
100
|
rd
|
0111011
|
DIVW
|
0000001
|
rs2
|
rs1
|
101
|
rd
|
0111011
|
DIVUW
|
0000001
|
rs2
|
rs1
|
110
|
rd
|
0111011
|
REMW
|
0000001
|
rs2
|
rs1
|
111
|
rd
|
0111011
|
REMUW
|
|
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
RV32A Standard Extension
|
00010
|
aq
|
rl
|
00000
|
rs1
|
010
|
rd
|
0101111
|
LR.W
|
00011
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
SC.W
|
00001
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOSWAP.W
|
00000
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOADD.W
|
00100
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOXOR.W
|
01100
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOAND.W
|
01000
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOOR.W
|
10000
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOMIN.W
|
10100
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOMAX.W
|
11000
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOMINU.W
|
11100
|
aq
|
rl
|
rs2
|
rs1
|
010
|
rd
|
0101111
|
AMOMAXU.W
|
RV64A Standard Extension (in addition to RV32A)
|
00010
|
aq
|
rl
|
00000
|
rs1
|
011
|
rd
|
0101111
|
LR.D
|
00011
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
SC.D
|
00001
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOSWAP.D
|
00000
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOADD.D
|
00100
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOXOR.D
|
01100
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOAND.D
|
01000
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOOR.D
|
10000
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOMIN.D
|
10100
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOMAX.D
|
11000
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOMINU.D
|
11100
|
aq
|
rl
|
rs2
|
rs1
|
011
|
rd
|
0101111
|
AMOMAXU.D
|
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
rs3
|
funct2
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R4-type
|
imm[11:0]
|
rs1
|
funct3
|
rd
|
opcode
|
I-type
|
imm[11:5]
|
rs2
|
rs1
|
funct3
|
imm[4:0]
|
opcode
|
S-type
|
RV32F Standard Extension
|
imm[11:0]
|
rs1
|
010
|
rd
|
0000111
|
FLW
|
imm[11:5]
|
rs2
|
rs1
|
010
|
imm[4:0]
|
0100111
|
FSW
|
rs3
|
00
|
rs2
|
rs1
|
rm
|
rd
|
1000011
|
FMADD.S
|
rs3
|
00
|
rs2
|
rs1
|
rm
|
rd
|
1000111
|
FMSUB.S
|
rs3
|
00
|
rs2
|
rs1
|
rm
|
rd
|
1001011
|
FNMSUB.S
|
rs3
|
00
|
rs2
|
rs1
|
rm
|
rd
|
1001111
|
FNMADD.S
|
0000000
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FADD.S
|
0000100
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FSUB.S
|
0001000
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FMUL.S
|
0001100
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FDIV.S
|
0101100
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FSQRT.S
|
0010000
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FSGNJ.S
|
0010000
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FSGNJN.S
|
0010000
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FSGNJX.S
|
0010100
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FMIN.S
|
0010100
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FMAX.S
|
1100000
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.W.S
|
1100000
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.WU.S
|
1110000
|
00000
|
rs1
|
000
|
rd
|
1010011
|
FMV.X.W
|
1010000
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FEQ.S
|
1010000
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FLT.S
|
1010000
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FLE.S
|
1110000
|
00000
|
rs1
|
001
|
rd
|
1010011
|
FCLASS.S
|
1101000
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.S.W
|
1101000
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.S.WU
|
1111000
|
00000
|
rs1
|
000
|
rd
|
1010011
|
FMV.W.X
|
RV64F Standard Extension (in addition to RV32F)
|
1100000
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.L.S
|
1100000
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.LU.S
|
1101000
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.S.L
|
1101000
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.S.LU
|
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
rs3
|
funct2
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R4-type
|
imm[11:0]
|
rs1
|
funct3
|
rd
|
opcode
|
I-type
|
imm[11:5]
|
rs2
|
rs1
|
funct3
|
imm[4:0]
|
opcode
|
S-type
|
RV32D Standard Extension
|
imm[11:0]
|
rs1
|
011
|
rd
|
0000111
|
FLD
|
imm[11:5]
|
rs2
|
rs1
|
011
|
imm[4:0]
|
0100111
|
FSD
|
rs3
|
01
|
rs2
|
rs1
|
rm
|
rd
|
1000011
|
FMADD.D
|
rs3
|
01
|
rs2
|
rs1
|
rm
|
rd
|
1000111
|
FMSUB.D
|
rs3
|
01
|
rs2
|
rs1
|
rm
|
rd
|
1001011
|
FNMSUB.D
|
rs3
|
01
|
rs2
|
rs1
|
rm
|
rd
|
1001111
|
FNMADD.D
|
0000001
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FADD.D
|
0000101
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FSUB.D
|
0001001
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FMUL.D
|
0001101
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FDIV.D
|
0101101
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FSQRT.D
|
0010001
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FSGNJ.D
|
0010001
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FSGNJN.D
|
0010001
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FSGNJX.D
|
0010101
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FMIN.D
|
0010101
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FMAX.D
|
0100000
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.S.D
|
0100001
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.D.S
|
1010001
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FEQ.D
|
1010001
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FLT.D
|
1010001
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FLE.D
|
1110001
|
00000
|
rs1
|
001
|
rd
|
1010011
|
FCLASS.D
|
1100001
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.W.D
|
1100001
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.WU.D
|
1101001
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.D.W
|
1101001
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.D.WU
|
RV64D Standard Extension (in addition to RV32D)
|
1100001
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.L.D
|
1100001
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.LU.D
|
1110001
|
00000
|
rs1
|
000
|
rd
|
1010011
|
FMV.X.D
|
1101001
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.D.L
|
1101001
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.D.LU
|
1111001
|
00000
|
rs1
|
000
|
rd
|
1010011
|
FMV.D.X
|
|
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
rs3
|
funct2
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R4-type
|
imm[11:0]
|
rs1
|
funct3
|
rd
|
opcode
|
I-type
|
imm[11:5]
|
rs2
|
rs1
|
funct3
|
imm[4:0]
|
opcode
|
S-type
|
|
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
rs3
|
funct2
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R4-type
|
imm[11:0]
|
rs1
|
funct3
|
rd
|
opcode
|
I-type
|
imm[11:5]
|
rs2
|
rs1
|
funct3
|
imm[4:0]
|
opcode
|
S-type
|
RV32Q Standard Extension
|
imm[11:0]
|
|
rs1
|
100
|
rd
|
0000111
|
FLQ
|
imm[11:5]
|
rs2
|
rs1
|
100
|
imm[4:0]
|
0100111
|
FSQ
|
rs3
|
11
|
rs2
|
rs1
|
rm
|
rd
|
1000011
|
FMADD.Q
|
rs3
|
11
|
rs2
|
rs1
|
rm
|
rd
|
1000111
|
FMSUB.Q
|
rs3
|
11
|
rs2
|
rs1
|
rm
|
rd
|
1001011
|
FNMSUB.Q
|
rs3
|
11
|
rs2
|
rs1
|
rm
|
rd
|
1001111
|
FNMADD.Q
|
0000011
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FADD.Q
|
0000111
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FSUB.Q
|
0001011
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FMUL.Q
|
0001111
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FDIV.Q
|
0101111
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FSQRT.Q
|
0010011
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FSGNJ.Q
|
0010011
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FSGNJN.Q
|
0010011
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FSGNJX.Q
|
0010111
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FMIN.Q
|
0010111
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FMAX.Q
|
0100000
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.S.Q
|
0100011
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.Q.S
|
0100001
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.D.Q
|
0100011
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.Q.D
|
1010011
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FEQ.Q
|
1010011
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FLT.Q
|
1010011
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FLE.Q
|
1110011
|
00000
|
rs1
|
001
|
rd
|
1010011
|
FCLASS.Q
|
1100011
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.W.Q
|
1100011
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.WU.Q
|
1101011
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.Q.W
|
1101011
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.Q.WU
|
RV64Q Standard Extension (in addition to RV32Q)
|
1100011
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.L.Q
|
1100011
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.LU.Q
|
1101011
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.Q.L
|
1101011
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.Q.LU
|
|
31
|
27
|
26
|
25
|
24
|
20
|
19
|
15
|
14
|
12
|
11
|
7
|
6
|
0
|
|
funct7
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R-type
|
rs3
|
funct2
|
rs2
|
rs1
|
funct3
|
rd
|
opcode
|
R4-type
|
imm[11:0]
|
rs1
|
funct3
|
rd
|
opcode
|
I-type
|
imm[11:5]
|
rs2
|
rs1
|
funct3
|
imm[4:0]
|
opcode
|
S-type
|
| RV32Zfh Standard Extension |
imm[11:0]
|
rs1
|
001
|
rd
|
0000111
|
FLH
|
imm[11:5]
|
rs2
|
rs1
|
001
|
imm[4:0]
|
0100111
|
FSH
|
rs3
|
10
|
rs2
|
rs1
|
rm
|
rd
|
1000011
|
FMADD.H
|
rs3
|
10
|
rs2
|
rs1
|
rm
|
rd
|
1000111
|
FMSUB.H
|
rs3
|
10
|
rs2
|
rs1
|
rm
|
rd
|
1001011
|
FNMSUB.H
|
rs3
|
10
|
rs2
|
rs1
|
rm
|
rd
|
1001111
|
FNMADD.H
|
0000010
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FADD.H
|
0000110
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FSUB.H
|
0001010
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FMUL.H
|
0001110
|
rs2
|
rs1
|
rm
|
rd
|
1010011
|
FDIV.H
|
0101110
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FSQRT.H
|
0010010
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FSGNJ.H
|
0010010
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FSGNJN.H
|
0010010
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FSGNJX.H
|
0010110
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FMIN.H
|
0010110
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FMAX.H
|
0100000
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.S.H
|
0100010
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.H.S
|
0100001
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.D.H
|
0100010
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.H.D
|
0100011
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.Q.H
|
0100010
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.H.Q
|
1010010
|
rs2
|
rs1
|
010
|
rd
|
1010011
|
FEQ.H
|
1010010
|
rs2
|
rs1
|
001
|
rd
|
1010011
|
FLT.H
|
1010010
|
rs2
|
rs1
|
000
|
rd
|
1010011
|
FLE.H
|
1110010
|
00000
|
rs1
|
001
|
rd
|
1010011
|
FCLASS.H
|
1100010
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.W.H
|
1100010
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.WU.H
|
1110010
|
00000
|
rs1
|
000
|
rd
|
1010011
|
FMV.X.H
|
1101010
|
00000
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.H.W
|
1101010
|
00001
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.H.WU
|
1111010
|
00000
|
rs1
|
000
|
rd
|
1010011
|
FMV.H.X
|
| RV64Zfh Standard Extension (in addition to RV32Zfh) |
1100010
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.L.H
|
1100010
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.LU.H
|
1101010
|
00010
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.H.L
|
1101010
|
00011
|
rs1
|
rm
|
rd
|
1010011
|
FCVT.H.LU
|
Table 2 lists the CSRs that have currently been
allocated CSR addresses. The timers, counters, and floating-point CSRs
are the only CSRs defined in this specification.
Table 2. RISC-V control and status register (CSR) address map.
| Number |
Privilege |
Name |
Description |
Floating-Point Control and Status Registers
|
0x001
|
Read write |
fflags
|
Floating-Point Accrued Exceptions. |
0x002
|
Read write |
frm
|
Floating-Point Dynamic Rounding Mode. |
0x003
|
Read write |
fcsr
|
Floating-Point Control and Status Register (frm + fflags). |
Counters and Timers
|
0xC00
|
Read-only |
cycle
|
Cycle counter for RDCYCLE instruction. |
0xC01
|
Read-only |
time
|
Timer for RDTIME instruction. |
0xC02
|
Read-only |
instret
|
Instructions-retired counter for RDINSTRET instruction. |
0xC80
|
Read-only |
cycleh
|
Upper 32 bits of cycle, RV32I only. |
0xC81
|
Read-only |
timeh
|
Upper 32 bits of time, RV32I only. |
0xC82
|
Read-only |
instreth
|
Upper 32 bits of instret, RV32I only. |
