Virtual JTAG Intel® FPGA IP Core User Guide

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ID 683705
Date 8/12/2021
Public
Document Table of Contents
Document Table of Contents x
Virtual JTAG Intel® FPGA IP Core User Guide
Virtual JTAG Intel® FPGA IP Core User Guide x
Introduction System-Level Debugging Infrastructure Virtual JTAG Interface Description Run-Time Communication Instantiating the Virtual JTAG Intel® FPGA IP Core Simulation Support Compiling the Design SLD_NODE Discovery and Enumeration Capturing the Virtual IR Instruction Register AHDL Function Prototype VHDL Component Declaration VHDL LIBRARY-USE Declaration Design Example: TAP Controller State Machine Design Example: Modifying the DCFIFO Contents at Runtime Design Example: Offloading Hardwired Revision Information Document Revision History for the Virtual JTAG Intel® FPGA IP Core User Guide
Introduction x
Installing and Licensing Intel® FPGA IP Cores On-Chip Debugging Tool Suite Applications of the Virtual JTAG Intel® FPGA IP Core JTAG Protocol JTAG Circuitry Architecture
System-Level Debugging Infrastructure x
Transaction Model of the SLD Infrastructure SLD Hub Finite State Machine
Virtual JTAG Interface Description x
Input Ports Output Ports Parameters Design Flow of the Virtual JTAG Intel® FPGA IP Core Simulation Model Run-Time Communication Running a DR Shift Operation Through a Virtual JTAG Chain
Run-Time Communication x
Virtual IR/DR Shift Transaction without Returning Captured IR/DR Values Virtual IR/DR Shift Transaction that Captures Current VIR/VDR Values Reset Considerations when Using a Custom JTAG Controller
Instantiating the Virtual JTAG Intel® FPGA IP Core x
IP Catalog and Parameter Editor Specifying IP Core Parameters and Options Instantiating Directly in HDL
IP Catalog and Parameter Editor x
The Parameter Editor
Specifying IP Core Parameters and Options x
Files Generated for Intel® FPGA IP Cores (Legacy Parameter Editor)
Compiling the Design x
Third-Party Synthesis Support
SLD_NODE Discovery and Enumeration x
Issuing the HUB_INFO Instruction HUB IP Configuration Register SLD_NODE Info Register
Design Example: Modifying the DCFIFO Contents at Runtime x
Write Logic Read Logic Runtime Communication
Design Example: Offloading Hardwired Revision Information x
Configuring the JTAG User Code Setting
Virtual JTAG Intel® FPGA IP Core User Guide

Virtual JTAG Interface Description

The Virtual JTAG Interface implements an SLD node interface, which provides a communication interface to the JTAG port. The IP core exposes control signals that are part of the SLD hub; namely, JTAG port signals, all finite state machine controller states of the TAP controller, and the SLD hub finite state machine. Additionally, each instance of the Virtual JTAG Intel® FPGA IP cores contain the virtual Instruction Register for the SLD node. Instantiation of this IP core automatically infers the SLD infrastructure, and one SLD node is added for each instantiation.

The Virtual JTAG Intel® FPGA IP core provides a port interface that mirrors the actual JTAG ports. The interface contains the JTAG port pins, a one‑hot decoded output of all JTAG states, and a one-hot decoded output of all the virtual JTAG states. Virtual JTAG states are the states decoded from the SLD hub finite state machine. The ir_in and ir_out ports are the parallel input and output to and from the VIR. The VIR ports are used to select the active VDR datapath. The JTAG states and TMS output ports are provided for debugging purposes only. Only the virtual JTAG, TDI, TDO, and the IR signals are functional elements of the IP core. When configuring this IP core using the parameter editor, you can hide TMS and the decoded JTAG states.

The figure below shows the input and output ports of the virtual JTAG Intel® FPGA IP core. The JTAG TAP controller outputs and TMS signals are used for informational purposes only. These signals can be exposed using the Create primitive JTAG state signal ports option in the parameter editor.

Figure 8. Input and Output Ports of the Virtual JTAG Intel® FPGA IP Core
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