The PMA transmitter uses a voltage mode driver supporting normal swing, low swing, and low-power low-swing mode. The predriver controller puts the driver in the correct states and selects the correct analog components. This module is tightly coupled with the function of the analog voltage mode driver and high-speed serial data selection multiplexer. The allowed states of the analog transmitters are as follows.
•Normal swing high-speed data transmission with and without allowed de-emphasis level for supported protocols.
•Low swing mode high-speed data transmission with and without allowed de-emphasis level for supported protocols.
•Electrical idle which holds the common mode at line.
•Putting the line in a high-Z state.
•Receiver detection state.
The data selection multiplexer selects data from various sources including serial data during LFPS. The low-power driver mode performs receiver detection through the predriver by selecting the appropriate data at the data selection multiplexer input and controlling the driver switches.