3. Configuration & Testing
C51003-1.3
All Cyclone® devices provide JTAG BST circuitry that complies with the
IEEE Std. 1149.1a-1990 specification. JTAG boundary-scan testing can be
performed either before or after, but not during configuration. Cyclone
devices can also use the JTAG port for configuration together with either
the Quartus® II software or hardware using either Jam Files (.jam) or Jam
Byte-Code Files (.jbc).
IEEE Std. 1149.1
(JTAG)Boundary
Scan Support
Cyclone devices support reconfiguring the I/O standard settings on the
IOE through the JTAG BST chain. The JTAG chain can update the I/O
standard for all input and output pins any time before or during user
mode. Designers can use this ability for JTAG testing before configuration
when some of the Cyclone pins drive or receive from other devices on the
board using voltage-referenced standards. Since the Cyclone device
might not be configured before JTAG testing, the I/O pins might not be
configured for appropriate electrical standards for chip-to-chip
communication. Programming those I/O standards via JTAG allows
designers to fully test I/O connection to other devices.
The JTAG pins support 1.5-V/1.8-V or 2.5-V/3.3-V I/O standards. The
TDO pin voltage is determined by the VCCIO of the bank where it resides.
The bank VCCIO selects whether the JTAG inputs are 1.5-V, 1.8-V, 2.5-V, or
3.3-V compatible.
Cyclone devices also use the JTAG port to monitor the operation of the
®
device with the SignalTap II embedded logic analyzer. Cyclone devices
support the JTAG instructions shown in Table 3–1.
Table 3–1. Cyclone JTAG Instructions (Part 1 of 2)
JTAG Instruction
Instruction Code
Description
00 0000 0101
Allows a snapshot of signals at the device pins to be captured and
examined during normal device operation, and permits an initial
data pattern to be output at the device pins. Also used by the
SignalTap II embedded logic analyzer.
SAMPLE/PRELOAD
00 0000 0000
11 1111 1111
Allows the external circuitry and board-level interconnects to be
tested by forcing a test pattern at the output pins and capturing test
results at the input pins.
EXTEST(1)
Places the 1-bit bypass register between the TDI and TDO pins,
which allows the BST data to pass synchronously through selected
devices to adjacent devices during normal device operation.
BYPASS
Altera Corporation
January 2007
3–1
Preliminary
ALTERA [ ALTERA CORPORATION ]
