Please clarify: it is either (1) you have an ADC with output bus, which needs to be sampled by PSoC; or (2) you have a DAC with bus input, which takes data from the PSoC. From your description it is hard do deduct what is going on. The best is to provide a part number.
There are ways to place the control registers side by side, so you can use one DMA transfer. Refer to this post:
Sorry, It's my mistake
It is not ADC but DAC.
Connect PSoC 5 LP and 16-bit DAC with parallel IO.
There is FIFOout component available, which was developed for fast parallel data output to the output bus. See #8 of thread:
It can be used with either CPU write or DMA transfer from RAM buffer. It utilizes 16-bit UDB 4-word deep FIFO buffer to smooth out transfer.