CP3UB17G38 NSC [National Semiconductor], CP3UB17G38 Datasheet - Page 67

• Manufacturer Part Number: CP3UB17G38
• Description: CP3UB17 Reprogrammable Connectivity Processor with USB Interface
• Manufacturer: NSC [National Semiconductor]

NodeResume
If the host has enabled remote wake-ups from the node, the
USB node can initiate a remote wake-up.
Once software detects the event, which wakes up the bus,
it releases the USB node from NodeSuspend state by initi-
ating a NodeResume on the USB using the NFSR register.
The node software must ensure at least 5 ms of Idle on the
USB. While in NodeResume state, a constant “K” is sig-
nalled on the USB. This should last for at least 1 ms and no
more than 5 ms, after which the USB host should continue
sending the NodeResume signal for at least an additional
20 ms, and then completes the NodeResume operation by
issuing the End Of Packet (EOP) sequence.
To successfully detect the EOP, software must enter the
USB NodeOperational state by setting the NFSR register.
If no EOP is received from the host within 100 ms, software
must re-initiate NodeResume.
NodeReset
When detecting a NodeResume or NodeReset signal while
in NodeSuspend state, the USB node can signal this to the
CPU by generating an interrupt.
USB specifications require that a device must be ready to
respond to USB tokens within 10 ms after wake-up or reset.
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