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

Write Logic

The RTL uses a single instance of the Virtual JTAG Intel® FPGA IP core to decode both the instructions for the write side and read side logic. The IR register is three bits wide, with the three instructions decoded in the RTL, as shown in the table below.
Table 16.  Instruction Register Values

Instruction Register Value

Function

PUSH

Instruction to write a single value to the write side logic of the DCFIFO.

POP

Instruction to read a single value from the read side logic of the DCFIFO

FLUSH

Instruction to perform a burst read transaction from the FIFO until empty.

The IR decode logic shifts the Push_in virtual DR chain when the PUSH instruction is on the IR port and virtual_state_sdr is asserted. A write enable pulse, synchronized to the write_clock, asserts after the virtual_state_udr signal goes high. The virtual_state_udr signal guarantees stability from the virtual DR chain. The figure below shows the write side logic for the DCFIFO.

Figure 20. Write Side Logic for DCFIFO
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