CYUSB3014 does support slave fifo in 32 Bit synchronous / asynchronous mode. Many of our customers use 32 Bit sync Slave fifo in CYUSB3014.
I agree that the details on sync slavefifo in Page 15 creates an impression like oly 16 Bit interface can be used for slave fifo. We apologize for the confusion. We will change it in our next revision of the datasheet.
- Madhu Sudhan