| Electronics > Projects, Designs, and Technical Stuff |
| When one PLD just isn't enough |
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| BrianHG:
--- Quote from: dexters_lab on February 26, 2018, 10:16:37 am ---no less than 82 Altera Flex EPF8282 PLDs! --- End quote --- Those PLDs arent big enough to do anything else than count, load/store a few bytes of data, address decode and mux/demux. They are not doing any 3D, blending, mixing. The LOGIC LF2246GC33 has 11 x 10 bit multipliers in a 2D matrix designed to be an image filter, so, it's doing deep color image processing. As for checking the data sheet, the EPF8282 is fast enough to mux/demux 32 bits into a 10 wire bus and back at 108MHz (8x the speed of NTSC/PAL sample clock of 13.5MHz, the pixel speed) / 4 equals sending 2 pixels/1 video sample clock, or add 32 bit address as well, means sending 1 pixel per sample period. Place them all over your PCB and you can send/receive pixels with address from any point A to any point B on your PCB with only 10 wires. Or, you can do this with multiple banks of 6 wires, one for address, one for pixel. Looking at all the memory and buffers and sections on the multiple boards of the quantel, this divides your wire count between sections by 8 fold and you can now have multiple dedicated buses. Especially when feeding the LOGIC LF2246GC33 multipliers from different frame and mask banks either stored or computed elsewhere on the paintbox. |
| BrianHG:
Remember, that memory isn't blazingly fast to begin with, and they have different CPU architectures all over the place & I'm sure on different PCBs as well. |
| fpgaarcade:
I used to work in Quantel R&D, if you have any questions from that period. I know the guy well who designed the image card, I worked on the slightly later stuff. /Mike |
| Mr. Scram:
--- Quote from: fpgaarcade on December 28, 2018, 03:49:51 pm ---I used to work in Quantel R&D, if you have any questions from that period. I know the guy well who designed the image card, I worked on the slightly later stuff. /Mike --- End quote --- Can you tell us more about the decisions that lead to this or similar designs? |
| fpgaarcade:
Sure, I'll respond later this evening. I joined Q in 93 ish so this card was just leaving R&D and going into production. I used a lot of the ideas on this card for the first generation of image processing on the HD machines. Interestingly, this card replaced three boards in the Henry system - which was great as it freed up slots for, well, more of them! /Mike |
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