AN 977: Nios® V Processor Custom Instruction

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ID 773194
Date 4/14/2023
Public
Document Table of Contents
Document Table of Contents x
1. Nios® V Processor Custom Instruction Overview 2. Custom Instruction Hardware Interface 3. Custom Instruction Software Interface 4. Designing with Intel® Quartus® Prime and Platform Designer 5. Document Revision History for AN 977: Nios® V Processor Custom Instruction
1. Nios® V Processor Custom Instruction Overview x
1.1. Implementing Custom Instruction 1.2. Implementing Custom Instruction Logic Block 1.3. Implementing Custom Instruction Software
2. Custom Instruction Hardware Interface x
2.1. Custom Instruction Types 2.2. Multicycle Custom Instructions 2.3. Extended Custom Instruction 2.4. External Interface Custom Instructions
2.2. Multicycle Custom Instructions x
2.2.1. Multicycle Custom Instruction Ports 2.2.2. Multicycle Custom Instruction Timing 2.2.3. Implementing Combinational Custom Instruction
2.3. Extended Custom Instruction x
2.3.1. Extended Custom Instruction Timing
3. Custom Instruction Software Interface x
3.1. Custom Instruction Software C Macro 3.2. Custom Instruction Assembly Language Interface 3.3. Custom Instruction Word Format
3.2. Custom Instruction Assembly Language Interface x
3.2.1. Custom Instruction Assembly Language Syntax Custom Instruction Assembly Language Syntax
3.3. Custom Instruction Word Format x
3.3.1. Selector and Extension Indexes 3.3.2. ALU Switch 3.3.3. User-defined Immediate
4. Designing with Intel® Quartus® Prime and Platform Designer x
4.1. Interface Signals 4.2. Custom Instruction Manager 4.3. Custom Instruction Subordinate
4.1. Interface Signals x
4.1.1. alu_result port 4.1.2. ctrl port
4.2. Custom Instruction Manager x
4.2.1. Hardware Interfaces Table 4.2.2. Software C-Macro Table
4.3. Custom Instruction Subordinate x
4.3.1. Writing the Custom Instruction HDL File 4.3.2. Opening the Component Editor 4.3.3. Specifying the Custom Instruction Component Type 4.3.4. Displaying the Custom Instruction Block Symbol 4.3.5. Adding the Custom Instruction HDL File 4.3.6. Configuring the Custom Instruction Parameter Type 4.3.7. Setting Up the Custom Instruction Interfaces 4.3.8. Saving and Adding the Custom Instruction 4.3.9. Generating and Compiling the Processor System
1. Nios® V Processor Custom Instruction Overview
2. Custom Instruction Hardware Interface
3. Custom Instruction Software Interface
4. Designing with Intel® Quartus® Prime and Platform Designer
5. Document Revision History for AN 977: Nios® V Processor Custom Instruction

3.2.1. Custom Instruction Assembly Language Syntax

Nios® V processor custom instructions use a standard assembly language syntax as shown in the following table:

Table 5.  Standard Assembly Language
Syntax Description
<mnemonic>
  • Identifies the particular custom instruction.
  • Assigned during system development in the Platform Designer.
<destination> Identifies the register that stores the result of the result port (if any).
<source 0> Identifies the register that provides the first input argument from the data0 port (if any).
<source 1> Identifies the register that provides the second input argument from the data1 port (if any).

The custom instruction designates the registers based on the application binary interface (ABI) name of each registers.

Custom Instruction Assembly Language Syntax

CUSTOM_OPERATION1, a5, a5, a4

The example above shows a call to a custom instruction, called CUSTOM_OPERATION1. The input to the instruction is the current contents of the Nios® V processor registers a5 and a4. Nios® V processor register a5 stores the results .

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