Lane Controller

The lane controller handles the complex operations necessary for the high-speed interfaces, such as DDR memory interfaces and CDR interfaces. To bridge the lane clock to the high-speed I/O clock, the lane controller is used to control an I/O FIFO in each IOD. This I/O FIFO interfaces with DDR memory by utilizing the DQS strobe on the lane clock. The lane controller can also delay the lane clock using a PVT-calculated delay code from the DLL to provide a 90° shift. Certain I/O interfaces require a lane controller to handle the clock-domain that results with higher gear ratios. For more information, see Generic I/O Interfaces.

The lane controller also provides the functionality for the IOD CDR. Using the four phases from the CCC PLL, the lane controller creates eight phases and selects the proper phase for the current input condition with the input data, see PF_IOD_CDR for more information. A divided-down version of the recovered clock is provided to the fabric (DIVCLK).