DS80PCI810: Hot plug function

Hi

The DS80PCI810 has been used in applications which can hot swap.  The built in receiver detection circuit accurately monitors and controls the PCI810 receiver impedance.  This function allows the system to reconfigure properly after each "new" insertion.  To retrigger this circuit, the PRSNT# input must be cycled during the hot-swap event.

Regards,

Lee

<Question1>
DS80PCI810 doesn't have PRSNT pin.  the DS80PCI810 changed the pin name to PWDN.

<Question2>
"the PRSNT# input must be cycled during the hot-swap event"
->We could not understand exactly.As our imagination, we configure High level incase of default, when it is possible to operate internally, we changes Low level?
Could you give us the advice?

The PWDN input on the DS80PCI810 must be held LOW for normal operation.  If the PCI Express bus using the DS80PCI810 experiences a "removal" event, then the PWDN pin should be pulled HIGH as the same time.  When the the endpoint is re-insterted and a "hot insertion" event occurs, the system should change the state of the PWDN input to LOW again.  This "cycling" or LOW - HIGH - LOW sequence will re-trigger the Rx-Detection circuitry so the PCIe system can reconfigure itself properly for the new endpoint.

<Question3>
CML Input Voltage is -0.5V upto VDD+0.5V.
When we use DS80PCI810 with using AC coupling, so we guess that actual Absolute Maximum Ratings CML Input Voltage depends on the breakdown voltage of AC coupling capacitance.
Is our recognition correct?

Normally the input common mode is biased to ~ VDD of the DS80PCI810.  The AC coupling on the input blocks the Tx common mode voltage from the connected output.  You car correct, this input common mode voltage will remain stable unless the breakdown voltage of the AC coupling is exceeded and the capacitor fails.

Regards,

Lee