2–222
Altera Corporation
Stratix II GX Device Handbook, Volume 2
October 2007
Reset Control and Power Down
2.
In the
Tasks
pane, execute
Report Unconstrained Paths
. This will
report all unconstrained paths in RED in the
Report
pane.
3.
Expand the
Unconstrained Paths
option in the
Report
pane and
further expand the
Setup Analysis
or
Hold Analysis
option.
4.
Under
Setup Analysis
or
Hold Analysis
, you will see
Unconstrained Input Port Paths
,
Unconstrained Output Port
Paths
, or both, depending on how the reset/powerdown ports are
driven.
a.
If a reset/powerdown port is driven by an input pin, it will be
listed in the
Unconstrained Input Port Paths
report.
b.
If a reset/powerdown port is driven by synchronous logic, it
will be listed in the
Unconstrained Output Port Paths
report.
5.
In the
Unconstrained Input Port Paths
and
Unconstrained Output
Port Paths
reports, the unconstrained reset/powerdown ports of
your ALT2GXB instances are listed under the
To
column.
Consider the design example in
Figure 2–163
.
Figure 2–163. Example Design for TimeQuest Timing Analyzer Constraints
In the design example in
Figure 2–163
, all reset/powerdown ports except
the
tx_digitalreset
port for the two channels are driven by the reset
controller. The
tx_digitalreset
port is driven from an input pin.
Figures 2–164
and
2–165
show the TimeQuest Timing Analyzer Report
for
Unconstrained Input Port Paths
and
Unconstrained Output Port
Paths
, respectively.
ALT2GXB
Channel 0
Reset Controller
ALT2GXB
Channel 1
top_tx_digitalreset
gxb_powerdown
rx_digitalreset
rx_analogreset