Around 256K data is stored as a bunch in memory and we need to convert this digital data to analog at once by applying it to AD5542A dac ic. As chip select need to go low to high after each 16 bit data to latch it to dac.
You need to implement an SPI interface on your FPGA. Then from the memory you have to convert the data to an SPI signal then send it to the AD5542A.
You can search the web how to implement the SPI on your FPGA. See sample app note below:
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