CY7C9689 device has two differential serial output drivers that drive the same serialized data stream out on pins OUTA± and OUTB±. Having a redundant output is particularly useful in systems where the serial data stream needs to be transmitted to two different destinations.
In systems where the serial data stream is transmitted to only one destination the other serial stream is truly redundant. In such cases, to reduce power dissipation, it is recommended to leave the reduntant output pins OUTx± unconnected and the associated CURSETx input tied to VDD. For example, if the data stream on pins OUTB± is redundant then OUTB± pins should be left unconnected and CURSETB should be tied to VDD.