EP3SE50F780I3N Altera, EP3SE50F780I3N Datasheet - Page 454

• Manufacturer Part Number: EP3SE50F780I3N
• Description: Stratix III
• Manufacturer: Altera

IEEE Std. 1149.1 BST Operation Control
Figure 13–11. EXTEST Shift Data Register Waveforms
13–16
Stratix III Device Handbook, Volume 1
TAP_STATE
TMS
TDO
TCK
TDI
SHIFT_IR
Instruction Code
EXTEST mode selects data differently than SAMPLE/PRELOAD mode.
EXTEST chooses data from the update registers as the source of the
output and output-enable signals. Once the EXTEST instruction code is
entered, the multiplexers select the update register data. Therefore, data
stored in these registers from a previous EXTEST or SAMPLE/PRELOAD
test cycle can be forced onto the pin signals. In the capture phase, the
results of this test data are stored in the capture registers and then shifted
out of TDO during the shift phase. You can then store new test data in the
update registers during the update phase.
The EXTEST waveform diagram in
SAMPLE/PRELOAD waveform diagram, except for the instruction code.
The data shifted out of TDO consists of the data that was present in the
capture registers after the capture phase. New test data shifted into the
TDI pin appears at the TDO pin after being clocked through the entire
boundary-scan register.
BYPASS Instruction Mode
The BYPASS mode is activated when an instruction code of all ones is
loaded in the instruction register. This mode allows the boundary scan
data to pass the selected device synchronously to adjacent devices when
no test operation of the device is needed at the board level. The
waveforms in
once the TAP controller is in the SHIFT_DR state. In this state, data signals
are clocked into the bypass register from TDI on the rising edge of TCK
and out of TDO on the falling edge of the same clock pulse.
EXIT1_IR
UPDATE_IR
SELECT_DR
Figure 13–12
CAPTURE_DR
show how scan data passes through a device
Data stored in
boundary-scan
register is shifted
out of TDO.
Figure 13–11
After boundary-scan
register data has been
shifted out, data
entered into TDI will
shift out of TDO.
resembles the
SHIFT_DR
Altera Corporation
November 2007
EXIT1_DR
UPDATE_DR