（笔记）自定义指令CRC Custom Instruction实例学习

环境

QII9.0 + NiosII9.0 IDE

1、手册中的步骤

Implementing Custom Instruction Hardware in SOPC Builder

Open the Component Editor

1. Open the SOPC Builder system.

2. On the SOPC Builder System Contents tab, double-click cpu.

The Nios II Processor configuration wizard appears.

3. On the Parameter Settings page, click the Custom Instructions tab.

4. Click Import. The component editor appears, displaying the Introduction tab.

Add the Synthesis HDL File

1. Click Next to display the HDL Files tab.

2. Click Add.

3. Browse to the directory containing the hardware description language (HDL) file(s), select the files needed, and click Open. The files to be added in this demonstration are

CRC_Custom_Instruction.v and CRC_Component.v located in crc_hw directory.

4. Turn on the Synth parameter for each of the HDL files added. This is to indicate that these files have synthesis equivalents. Both HDL files imported in this demonstration have synthesis equivalents

5. Turn on the Top parameter to indicate where the top-level HDL file is. The top-level HDL file for this demonstration is CRC_Custom_Instruction.v.

6. Click Top Level Module and select the name of the top-level module of your custom instruction logic. The top-level module of the design in this demonstration is CRC_Custom_Instruction.

Configure the Custom Instruction Signal Type

1.Click Next to display the Signals tab. There are several ports (signals) listed.

2. For every port listed, carry out the following steps:

a. Select the port.

b. In the Interface drop-down list, select the interface name you wish to assign the port with,

c. In the Signal Type drop-down list, select the signal type corresponding to the port name. For example, if the custom instruction hardware presents the result on a port named output, you set the Signal Type to result.

Set Up Custom Instruction Interfaces

1. Click Next to display the Interfaces tab. The default interface type displayed is Custom Instruction Slave.

2. Rename the interface by typing the desired name in the Name field. You can use the default name if you do not intend to change the

name.

3. Set the Operands parameter value to the number of operands used for the custom instruction. The custom instruction used in this demonstration has only one operand, so set the Operands parameter to one.

4. If you are using fixed multi-cycle type custom instruction, set the Clock Cycles parameter value to the number of clock cycles your custom instruction logic needs. The design in this demonstration is of variable multi-cycle type, so set the Clock Cycles parameter to zero.