DS80PCI800: the difference between PWDN power down,0x01 and Rx detect State Machine Reset,0x02[7:6]

Hi Kato-san,

1. Using Reg 0x01 will power down the channel. Powering up again has no effect on the Rx Detect State Machine.

2. Using Reg 0x02 to reset the Rx Detect State Machine will re-initialize the DS80PCI800 to test whether an endpoint is connected to the output of each DS80PCI800 channel. Normally, Rx Detect State Machine begins when the DS80PCI800 is powered up or power-cycled. Once the device asserts that an endpoint is detected, the DS80PCI800 applies the internal 50-ohm input termination to the respective input.

Once Rx Detect is asserted, the 50-ohm input termination will remain connected. In order to reset the Rx Detect State Machine without power cycling the DS80PCI800, you must either (1) the PRSNT# pin is held high for at least 5 us OR (2) the Rx Detect State Machine is overridden by Reg 0x02[7:6].

Thanks,

Michael