Altera Cyclone V Device Handbook page 266

9-4
Supported JTAG Instruction
JTAG Instruction
EXTEST
BYPASS
USERCODE
IDCODE
Altera Corporation
Instruction Code
00 0000 1111
11 1111 1111
00 0000 0111
00 0000 0110
Description
Allows you to test the external
circuit and board-level intercon-
nects by forcing a test pattern at the
output pins, and capturing the test
results at the input pins. Forcing
known logic high and low levels on
output pins allows you to detect
opens and shorts at the pins of any
device in the scan chain.
The high-impedance state of
is overridden by bus hold and weak
pull-up resistor features.
Places the 1-bit bypass register between
the and pins. During normal
TDI TDO
device operation, the 1-bit bypass
register allows the BST data to pass
synchronously through the selected
devices to adjacent devices.
Examines the user electronic
signature (UES) within the devices
along a JTAG chain.
Selects the 32-bit
USERCODE
and places it between the
pins to allow serial shifting of
TDO
out of
USERCODE TDO
The UES value is set to default value
before configuration and is only
user-defined after the device is
configured.
Identifies the devices in a JTAG
chain. If you select
device identification register is
loaded with the 32-bit
vendor-defined identification code.
Selects the
IDCODE
places it between the
pins to allow serial shifting of
out of .
IDCODE TDO
is the default instruction at
IDCODE
power up and in the
state. Without loading any instruc-
tions, you can go to the
state and shift out the JTAG device
ID.
JTAG Boundary-Scan Testing in Cyclone V Devices
CV-52009
2014.01.10
EXTEST
register
and
TDI
.
, the
IDCODE
register and
and
TDI TDO
TAP RESET
SHIFT_DR
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