10-05-2019 03:30 AM
I have an HLS module that requires large FIFOs inside an dataflow region. I used hls::stream. For these i want HLS to use UltraRam, but i could not find a way how to tell HLS to biuld the FIFOs with ultra ram.
The Resource pragma only allows FIFO, FIFO_LUTRAM, FIFO_BRAM and FIFO_SRL. I could think of splitting the module in two and put normal fifo ip's in between, but that is not really the preferred way. Is there a way to use ultraram in hls::stream fifos?
10-06-2019 03:13 AM
@emc_three The fundamental problem is that, unlike BRAM, UltraRAM doesn't include FIFO hardware. Using it as a FIFO would require separate hardware implemented in LUTs, and it appears that neither HLS nor the Vivado FIFO generator knows how to do this.