Hi Mel,
Please refer to Figure 2 and Figure 4 in the data sheet. You'll notice that Ch A data is output on the rising edge of the DCO clock while Ch B is output on the falling edge of the DCO clock. Likewise, Ch C is output on the rising edge of the DCO clock while Ch D is output on the falling edge of the DCO clock. Data from Ch A and Ch B is output on the port D0AB through D10AB while data from Ch C and Ch D is output on the port D0CD through D10CD. For every one input sample clock period the data from ALL channels is output on the data ports.
Regards,
Jonathan