9.4.1 Input Clock Edge

The transmission of data bits D0 through D27 occurs as each are loaded into registers upon the edge of the CLKIN signal, where the rising or falling edge of the clock may be selected through CLKSEL. The selection of a clock rising edge occurs by inputting a high level to CLKSEL, which is achieved by populating pullup resistor to pull CLKSEL=high. Inputting a low level to select a clock falling edge is achieved by directly connecting CLKSEL to GND.