EP2C5T144I8N Datasheet, PDF (430/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

IEEE Std. 1149.1 Boundary-Scan Register
operate the TAP controller, and the TDI and TDO pins provide the serial
path for the data registers. The TDI pin also provides data to the
instruction register, which then generates control logic for the data
registers.
IEEE Std. 1149.1
Boundary-Scan
Register
The boundary-scan register is a large serial shift register that uses the TDI
pin as an input and the TDO pin as an output. The boundary-scan register
consists of 3-bit peripheral elements that are associated with Cyclone II
I/O pins. You can use the boundary-scan register to test external pin
connections or to capture internal data.
f
See the Configuration & Testing chapter in Volume 1 of the Cyclone II
Device Handbook for the Cyclone II device boundary-scan register
lengths.
Figure 14–3 shows how test data is serially shifted around the periphery
of the IEEE Std. 1149.1 device.
Figure 14–3. Boundary-Scan Register
Internal Logic
Each peripheral
element is either an
I/O pin, dedicated
input pin, or
dedicated
configuration pin.
TAP Controller
TDI
TMS
TCK
TDO
Boundary-Scan Cells of a Cyclone II Device I/O Pin
The Cyclone II device 3-bit boundary-scan cell (BSC) consists of a set of
capture registers and a set of update registers. The capture registers can
connect to internal device data via the OUTJ and OEJ signals, and connect
14–4
Cyclone II Device Handbook, Volume 1
Altera Corporation
February 2007