Why doesn’t the tx_pma_elecidle signal on the Intel® Arria® 10 or Cyclone® 10 GX device Native PHY IP put the transceiver TX pins in a tristate or high-impedance mode?

Asserting the tx_pma_elecidle signal on the Intel Arria 10 or Cyclone 10 GX device Native PHY IP does not tristate or put the transceiver TX pins in a high-impedance mode.

Asserting the tx_pma_elecidle signal on the Intel Arria 10 or Cyclone 10 GX device Native PHY IP stops data transmission and causes the output signal to exhibit the Transmitter Vocm on both P and N pins of the differential pair.

The TX termination remains connected to the Vcm generator when the tx_pma_elecidle signal is asserted.   

This information may be added to a future version of the Intel Arria 10 Transceiver PHY User Guide and Intel Cyclone 10 GX Transceiver User Guide.