Altera Virtual JTAG IP Core - Manual (Page 10)

The figure below shows the input and output ports of the virtual JTAG megafunction. 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 on page 3 of the MegaWizard Plug-In Manager.
Figure 7: Input and Output Ports of the Virtual JTAG Megafunction
Inputs
One-Hot Decoded Outputs
from the SLD Hub FSM
One-Hot Decoded Outputs
from the TAP Controller
Input Ports
Table 2: Input Ports for the Virtual JTAG Megafunction
Comments Description Required Port name
Writes to the TDO pin on the
device. Yes
tdo
Input port [SLD_IR_WIDTH-
1..0]
wide. Specify the width
of this bus with the SLD_IR_
WIDTH
parameter.
Virtual JTAG instruction register
output. The value is captured
whenever
virtual_state_cir is
high.
No ir_out[]
Virtual JTAG Megafunction (sld_virtual_jtag) Altera Corporation
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Input Ports 10
2014.03.19