Platform Cable USB II
System Suspend
The cable's status LED is extinguished when the host system enters a suspend (power-saving) state. A system can suspend
for a number of reasons. For example:
•
•
•
•
The user puts the host system into standby or hibernate.
The suspend function key on a laptop computer is pressed.
The display panel of a laptop is closed.
The host system is configured to suspend (standby or hibernate) after a specified amount of inactivity.
The current drawn by the cable while suspended depends on the type of suspend state: standby or hibernate. While the host
system is in standby, the cable draws approximately 350 µA from the USB port. When the host is hibernating, all power is
removed from the USB ports so the cable draws no current while in this state.
The target interface output drivers are not powered while the host is suspended. These signals float to any DC bias level
provided by the target hardware during suspend.
If an iMPACT (10.1 or later) operation is in progress when suspend is attempted, iMPACT displays a message (Figure 9)
indicating that suspend is blocked until the operation is complete or manually aborted.
Note: This feature is not supported in earlier versions of iMPACT, while iMPACT is operating in batch mode, or by other Xilinx design
tools. In these cases, it is recommended that suspend be disabled in the host system when performing long, continuous operations.
The cable is automatically disconnected when the host system is suspended. A reconnect is necessary when the host re-
awakens from the suspend state (see Connecting to the Cable in iMPACT, page 5).
X-Ref Target - Figure 9
DS593_09_021408
Figure 9: Suspend Warning When iMPACT (10.1 or later) is Busy
Platform Cable USB II Connections
This section discusses physical connections from Platform Cable USB II to the host PC and the target system.
High Performance Ribbon Cable
A 6-inch ribbon cable is supplied and recommended for connection to target systems (Figure 10). The cable incorporates
multiple signal-ground pairs and facilitates error-free connections. The Xilinx product number for the 6-inch ribbon cable is
HW-RIBBON14.
To take advantage of the ribbon cable, a mating connector must be incorporated into the target system. This connector is
normally installed only during prototype checkout. When the production hardware is functional and the ISP devices can be
configured from alternate sources, the connector can be eliminated to reduce cost. Maintaining the footprint for this
connector is recommended if space permits.
DS593 (v1.2.1) March 17, 2011
www.xilinx.com
11
XILINX [ XILINX, INC ]
