Altera_Forum
Honored Contributor
10 years agoArria 10 GX configuation time vs. PCIe requirement
I've been charged with figuring out a configuration scheme for our Arria 10 design that will incorporate a PCIe interface. I've attached an image of what I've come up with
There is a 100ms configuration requirement if you are using PCIe. So to get my device to configure (270K GX part 10AX027H3F35), I have learned that basically we'll have to do a x32 configuration scheme running at 100MHz between our configuration host (MAXV with parallel flash loader) and the FPGA. This should load our FPGA in 38.4ms. The problem I am having is that I have to use FLASH storage for the bit file, and I just can't see how we can pull data out of the FLASH fast enough to feed the HOST => FPGA interface. I'm doing a 32 bit interface to the flash as well, using two 16 bit FLASH parts, and the "Parallel Flash Loader IP Core User Guide" says that the flash_clk speed is half the core source clock (125MHz/2 =62.5Mhz). Doing rough math, even at the most optimal burst rate:- 122,591,622 bits for Arria 10 10AX027H3F35.
- 32 bit interface from FLASH to HOST
- 32 bits from HOST to FPGA configuration interface
- 122,591,622/32 bits = 3830988 cycles @ 62.5MHZ (optimum BURST rate - not realistic full time) = 3830988*16nS = 61mS.
- The above 61ms < 100mS. Sounds fine, but read on.
- 351,292,512 bits for Arria 10 10AX1157N2F35.
- 32 bit interface from FLASH to HOST
- 32 bits from HOST to FPGA configuration interface
- 351,292,512/32 bits = 10977891 cycles @ 25MHZ - yes their config HOST clk is 50Mhz (optimum BURST rate - not realistic full time) = 10977891*40nS = 439mS.
- The above 439ms >> 100mS. This makes PCIe use impossible.