Shulou(Shulou.com)06/01 Report--

This article mainly shows you "what is the format of RISC-V instructions", the content is easy to understand, clear, hope to help you solve your doubts, the following let the editor lead you to study and learn "what is the format of RISC-V instructions" this article?

1. In the ISA of RISC-V, there are four core instruction formats, namely, R class, I class, S class and U class.

All instructions are 32 bits long; all instructions RS1 and RS2 are source registers and RD are destination registers

Class R:

Bit 31:25: function code, 7bit

Bit24:20:RS2,5bit

Bit19:15:RS1,5bit

Bit14:12 function code, 3bit

Bit11:7 RD,5bit

Bit6:0 opcode opcode, 7bit

RISU instructions, bit0-6 are all opcodes. The 7bit opcode represents 128 different instructions.

RISC-V, instruction basic format RISU, memory RISCV-- > RISU

R type, register-register type, basic format RD = RS1 op RS2 mode

I type, register-immediate number type, basic format RD= RS op immediate number

S type

There are 47 instructions in RISC-V 32i instruction

Class R type instructions: 10

ADD,SUB,SLL,SLT,SLTU,XOR,SRL,SRA,OR,AND

Class I instruction: 15

JALR,LB,LH,LW,LBU,LHU,ADDI,SLTI,SLTIU,XORI,ORI,ANDI,SLLI,SRLI,SRAI

Class S instructions: 9

BEQ,BNE,BLT,BGE,BLTU,BGEU,SB,SH,SW

Class U instructions: 3

LUI,AUIPC,JAL

Not clear for the time being: 10

FENCE,FENCE.I, ECALL,EBREA, CSRRW, CSRRS, CSRRC, CSRRW, CSRRSI, CSRRCI

The above is all the content of this article "what is the format of RISC-V instructions?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.