Virtual JTAG Intel® FPGA IP Core User Guide

ID 683705
Date 8/12/2021
Public
Document Table of Contents

Runtime Communication

The Tcl script, dc_fifo_vji.tcl, contains three procedures, each corresponding to one of the virtual JTAG instructions. The table below describes each of the procedures.
Table 17.  Run-Time Communication Tcl Procedures

Procedure

Description

push [value]

IR shift the PUSH instruction, followed by a DR shift of the value argument. Value must be an integer less than 256.

pop

IR shift the POP instruction, followed by a DR shift of 8 bits.

flushfifo

IR shift the FLUSH instruction.

The figure below shows runtime execution of eight values pushed into the DCFIFO and a flushfifo command, and a Signal Tap logic analyzer capture triggering on a flush operation.

Figure 22. Runtime Execution
Figure 23.  Signal Tap Logic Analyzer Capture Triggering on a Flush Operation