Reproduced the basic logic unit comparison of Xilinx and Altera FPGAs

Source: Internet
Author: User

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To compare Xilinx and Altera FPGAs, it is necessary to understand the structure of two giant FPGA, because of their respective interests, the two FPGA structure is different, the parameters are different, but can be unified to the LUT (look-up-table) lookup table.

Take the example of Altera's Cyclone II series Ep2c35, as well as the xc3s500e of the Xilinx spartan-3e series. You can refer to datasheet.

Cyclone II


Where Altera's Le and xilnx LC correspond to the structure of the LUT.


From the structure of Le can know 1 LE = 1 LUT


Logic Cell = 4-input look-up Table (LUT) + a ' D ' flip-flop;

Datasheet on the formula : "equivalent Logic Cells" equals "Total clbs" x 8 Logic cells/clb x 1.125 Effectiveness

That is:9LES/CLB ;

is a 1 Slice structure, from the Slice structure can be seen 1 CLB =4 slice=9 LC

This allows you to know the correspondence between Xilinx and Altera FPGA logical resources:

( in order to unify weights and measures (feeling like qsh), the industry generally boils down to BLM (Basic Logic Module)

1 BLM =1 LUT4 (four input lookup table) +1 register (can be configured as 1 trigger DFF or 1 latch) + multiplexer mux

1 BLM =1 LC (Xilinx) =4/9 Slice (Xilinx) = 1/9 CLB (Xilinx) =1 LE (Altera)

=0.125 LAB (Altera)=2.25 Tile (Actel)

So we can know that Altera's Cyclone II series of EP2C35 have 33,216 lut, I use the Xilinx spartan-3e series xc3s500e has 9,312 Lut, plus ep2c35 and 4 PLLs, My xc3s500e is more than that.

Reproduced the basic logic unit comparison of Xilinx and Altera FPGAs

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