Nios® V Processor Reference Manual

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ID 683632
Date 10/07/2024
Public
Document Table of Contents
Document Table of Contents x
1. Overview 2. Nios® V/c Processor 3. Nios® V/m Processor 4. Nios® V/g Processor 5. Nios V Processor Reference Manual Archives 6. Document Revision History for the Nios® V Processor Reference Manual
1. Overview x
1.1. Quartus® Prime Software Support
2. Nios® V/c Processor x
2.1. Processor Performance Benchmarks 2.2. Processor Pipeline 2.3. Processor Architecture 2.4. Programming Model 2.5. Core Implementation
2.3. Processor Architecture x
2.3.1. General-Purpose Register File 2.3.2. Arithmetic Logic Unit 2.3.3. Reset and Debug Signals 2.3.4. Memory and I/O Organization 2.3.5. Error Correction Code (ECC)
2.3.4. Memory and I/O Organization x
2.3.4.1. Instruction and Data Buses 2.3.4.2. Address Map
2.3.4.1. Instruction and Data Buses x
2.3.4.1.1. Instruction Manager Port 2.3.4.1.2. Data Manager Port 2.3.4.1.3. Choosing a Suitable Interface
2.4. Programming Model x
2.4.1. Privilege Levels
2.5. Core Implementation x
2.5.1. Instruction Set Reference
3. Nios® V/m Processor x
3.1. Processor Performance Benchmarks 3.2. Processor Pipeline 3.3. Processor Architecture 3.4. Programming Model 3.5. Core Implementation
3.1. Processor Performance Benchmarks x
3.1.1. Pipelined 3.1.2. Non-pipelined
3.2. Processor Pipeline x
3.2.1. Pipelined Architecture 3.2.2. Non-pipelined Architecture
3.3. Processor Architecture x
3.3.1. General-Purpose Register File 3.3.2. Arithmetic Logic Unit 3.3.3. Reset and Debug Signals 3.3.4. Control and Status Registers 3.3.5. Trap Controller 3.3.6. Memory and I/O Organization 3.3.7. RISC-V based Debug Module 3.3.8. Error Correction Code (ECC)
3.3.5. Trap Controller x
3.3.5.1. Exception Handling 3.3.5.2. Interrupt Handling
3.3.5.2. Interrupt Handling x
3.3.5.2.1. Timer and Software Interrupt Module
3.3.6. Memory and I/O Organization x
3.3.6.1. Instruction and Data Buses 3.3.6.2. Address Map
3.3.6.1. Instruction and Data Buses x
3.3.6.1.1. Instruction Manager Port 3.3.6.1.2. Data Manager Port 3.3.6.1.3. Choosing a Suitable Interface
3.3.7. RISC-V based Debug Module x
3.3.7.1. Debug Mode 3.3.7.2. Halt from Debug Module 3.3.7.3. Trigger 3.3.7.4. Abstract Commands in Debug Mode 3.3.7.5. Hardware/Software Interface
3.4. Programming Model x
3.4.1. Privilege Levels 3.4.2. Control and Status Registers (CSR) Mapping
3.4.1. Privilege Levels x
3.4.1.1. Machine Mode (M-mode) 3.4.1.2. Debug Mode (D-mode)
3.4.2. Control and Status Registers (CSR) Mapping x
3.4.2.1. Control and Status Register Field
3.5. Core Implementation x
3.5.1. Instruction Set Reference
4. Nios® V/g Processor x
4.1. Processor Performance Benchmarks 4.2. Processor Pipeline 4.3. Processor Architecture 4.4. Programming Model 4.5. Core Implementation
4.3. Processor Architecture x
4.3.1. General-Purpose Register File 4.3.2. Arithmetic Logic Unit 4.3.3. Multipy and Divide Units 4.3.4. Floating-Point Unit 4.3.5. Custom Instruction 4.3.6. Reset and Debug Signals 4.3.7. Control and Status Registers 4.3.8. Trap Controller 4.3.9. Memory and I/O Organization 4.3.10. RISC-V based Debug Module 4.3.11. Error Correction Code (ECC) 4.3.12. Branch Prediction 4.3.13. Lockstep Module
4.3.4. Floating-Point Unit x
4.3.4.1. IEEE 754 Exception Conditions 4.3.4.2. Floating Point Operations
4.3.4.2. Floating Point Operations x
4.3.4.2.1. Floating Point Classification
4.3.8. Trap Controller x
4.3.8.1. Exception Controller 4.3.8.2. Interrupt Controller
4.3.8.2. Interrupt Controller x
4.3.8.2.1. Timer and Software Interrupt Module
4.3.9. Memory and I/O Organization x
4.3.9.1. Instruction and Data Buses 4.3.9.2. Address Map 4.3.9.3. Cache Memory 4.3.9.4. Tightly Coupled Memory
4.3.9.1. Instruction and Data Buses x
4.3.9.1.1. Instruction Manager Port 4.3.9.1.2. Data Manager Port
4.3.9.3. Cache Memory x
4.3.9.3.1. Instruction Cache 4.3.9.3.2. Data Cache 4.3.9.3.3. Configurable Cache Memory 4.3.9.3.4. Bypassing Cache (Peripheral Region) 4.3.9.3.5. Using Cache Memory Effectively
4.3.9.4. Tightly Coupled Memory x
4.3.9.4.1. Instruction and Data Tightly Coupled Memory 4.3.9.4.2. Accessing Tightly Coupled Memory 4.3.9.4.3. Using Tightly Coupled Memory Effectively
4.3.10. RISC-V based Debug Module x
4.3.10.1. Debug Mode 4.3.10.2. Halt from Debug Module 4.3.10.3. Trigger 4.3.10.4. Abstract Commands in Debug Mode 4.3.10.5. Hardware/Software Interface
4.3.11. Error Correction Code (ECC) x
4.3.11.1. ECC Interface 4.3.11.2. ECC Error Injection 4.3.11.3. Affected CSR during ECC Event
4.4. Programming Model x
4.4.1. Privilege Levels 4.4.2. Control and Status Registers (CSR) Mapping
4.4.1. Privilege Levels x
4.4.1.1. Machine Mode (M-mode) 4.4.1.2. Debug Mode (D-mode)
4.4.2. Control and Status Registers (CSR) Mapping x
4.4.2.1. Control and Status Register Field
4.5. Core Implementation x
4.5.1. Instruction Set Reference
1. Overview
2. Nios® V/c Processor
3. Nios® V/m Processor
4. Nios® V/g Processor
5. Nios V Processor Reference Manual Archives
6. Document Revision History for the Nios® V Processor Reference Manual

4.5.1. Instruction Set Reference

The Nios® V/g processor is based on the RV32IMZicsr_Zicbom specification, optionally “F” extension. RV32IMZicsr_Zicbom includes:
  • RV32I base integer instruction ("I" extension)
  • Integer multiplication and division instructions ("M" extension)
  • Control and status register instructions ("Zicsr" extension)
  • Base cache management operation ISA ("CMO" extension)
  • Optionally, single-precision floating-point instruction ("F" extension)

There are 6 types of instruction formats. They are R-type, I-type, S-type, B-type, U-type, and J-type.

Besides the ‘CMO’ extension from RISC-V, Altera also provides customized cache management instructions. Refer to Data Cache for more information.

Table 112.  Instruction Formats (R-type)
Bit Field (R-type)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
funct7 rs2 rs1
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
rs1 funct3 rd opcode
Table 113.  Instruction Formats (I-type)
Bit Field (I-type)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
imm[11:0] rs1
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
rs1 funct3 rd opcode
Table 114.  Instruction Formats (S-type)
Bit Field (S-type)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
imm[11:5] rs2 rs1
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
rs1 funct3 imm[4:0] opcode
Table 115.  Instruction Formats (B-type)
Bit Field (B-type)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
imm[12] imm[10:5] rs2 rs1
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
rs1 funct3 imm[4:1] imm[11] opcode
Table 116.   Instruction Formats (U-type)
Bit Field (U-type)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
imm[31:16]
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
imm[15:12] rd opcode
Table 117.  Instruction Formats (J-type)
Bit Field (J-type)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
imm[20] imm[10:1] imm[11] imm[19:16]
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
imm[15:12] rd opcode
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