1. Nios II Custom Instruction Overview
2. Custom Instruction Hardware Interface
3. Custom Instruction Software Interface
4. Design Example: Cyclic Redundancy Check
5. Introduction to Nios® II Floating Point Custom Instructions
6. Nios II Floating Point Hardware 2 Component
7. Nios® II Floating Point Hardware (FPH1) Component
8. Document Revision History for Nios II Custom Instruction User Guide
4.1.1. Setting up the Environment for the CRC Example Design
4.1.2. Opening the Component Editor
4.1.3. Specifying the Custom Instruction Component Type
4.1.4. Displaying the Custom Instruction Block Symbol
4.1.5. Adding the CRC Custom Instruction HDL Files
4.1.6. Configuring the Custom Instruction Parameter Type
4.1.7. Setting Up the CRC Custom Instruction Interfaces
4.1.8. Configuring the Custom Instruction Signal Type
4.1.9. Saving and Adding the CRC Custom Instruction
4.1.10. Generating and Compiling the CRC Example System
6.1. Overview of the Floating Point Hardware 2 Component
6.2. Floating Point Hardware 2 IEEE 754 Compliance
6.3. IEEE 754 Exception Conditions with FPH2
6.4. Floating Point Hardware 2 Operations
6.5. Building the FPH2 Example Hardware
6.6. Building the FPH2 Example Software
6.7. FPH2 Implementation of GCC Options
6.8. Nios II FPH2 and the Newlib Library
6.9. C Macros for round(), fmins(), and fmaxs()
4.1.7.1. Specifying Additional Interfaces
You can specify additional interfaces in the Interfaces tab.
You can specify additional interfaces if your custom instruction logic requires special interfaces, either to the Avalon® -Memory Mapped fabric or outside the Platform Designer system. The design example does not require additional interfaces.
Note: Most custom instructions use some combination of standard custom instruction ports, such as dataa, datab, and result, and do not require additional interfaces.
The following instructions provide the information you need if a custom instruction in your own design requires additional interfaces. You do not need these steps if you are implementing the design example.
To specify additional interfaces on the Interfaces tab, follow these steps:
- Click Add Interface. The new interface has Custom Instruction Slave interface type by default.
- For Type, select the desired interface type.
- Set the parameters for the newly created interface according to your system requirements.