Altera Quartus II Scripting - Manual (Page 285)

Chapter 3: Tcl Packages & Commands 3–155
jtag
© July 2013 Altera Corporation Quartus II Scripting Reference Manual
device_virtual_ir_shift
Usage
device_virtual_ir_shift -instance_index <instance index> -ir_value <instruction
register value> [-no_captured_ir_value] [-show_equivalent_device_ir_dr_shift]
Options
-instance_index <instance index>: The index of the virtual JTAG instance
-ir_value <instruction register value>: Value of numeric oprand type to be written into
the instruction register in this instance
-no_captured_ir_value: Option to not return the captured instruction register value.
If this is specified, this IR scan may be packed together with the subsequent IR or DR
scan until the device is unlocked or a captured value is requested
-show_equivalent_device_ir_dr_shift: Option to show equivalent device ir and dr shifts
performed by this command
Description
Writes the specified value into the instruction register of the specified virtual JTAG instance in the open
device. Returns the captured instruction register value. You can disable the captured value return to
improve the JTAG communication speed by packing multiple IR or DR scans together.
The command also activates the target instance such that the consequent virtual DR shift operations are
applied to this instance before the device is unlocked. Before any virtual DR shift operation, this
command must be executed first to activate the instance.
The device must be locked first before this operation.
Example
# List all available programming hardwares, and select the USBBlaster.
# (Note: this example assumes only one USBBlaster connected.)
puts "Programming Hardwares:"
foreach hardware_name [get_hardware_names] {
puts $hardware_name
if { [string match "USB-Blaster*" $hardware_name] } {
set usbblaster_name $hardware_name
}
}
puts "\nSelect JTAG chain connected to $usbblaster_name.\n";
# List all devices on the chain, and select the first device on the
# chain.
puts "\nDevices on the JTAG chain:"
foreach device_name [get_device_names -hardware_name $usbblaster_name] {
puts $device_name
if { [string match "@1*" $device_name] } {
set test_device $device_name
}
}
puts "\nSelect device: $test_device.\n";
# Open device
open_device -hardware_name $usbblaster_name -device_name $test_device
# The follow virtual JTAG IR and DR shift sequence engage with
# the example virtual JTAG instance.
#
# Two instructions: SAMPLE (1) FEED (2)
# SAMPLE instruction samples a 8-bit bus; the captured value shows the