Configurable Logic Blocks (CLBs) implement most of the logic in an FPGA. The following CLB Count table lists FPGA design elements in alphanumeric order with the number of CLBs needed for their implementation in each applicable library. Refer to the Applicable Architectures section of the Xilinx Unified Libraries chapter for information on the specific device architectures supported in each library.
Each XC5200 CLB contains four independent Logic Cells (LCs). In the following table, the numbers in the XC5200 column are the LC4 count.
Each Virtex CLB contains two slices. In the following table, the numbers in the Virtex column are the combined count for the two slices.
This information is for reference only. The actual count could vary, depending upon the switch settings of the implementation tools; for example, the effort level in PAR (Place and Route).
Name | XC3000 | XC4000E | XC4000X | XC5200* | Spartan | SpartanXL | Virtex** |
---|---|---|---|---|---|---|---|
ACC4 | 9 | 7 | 7 | 15 | 7 | 7 | 5 |
ACC8 | 17 | 11 | 11 | 27 | 11 | 11 | 9 |
ACC16 | 33 | 19 | 19 | 51 | 19 | 19 | 17 |
ACLK | 1 | - | - | - | - | - | - |
ADD4 | 5 | 4 | 4 | 10 | 4 | 4 | 3 |
ADD8 | 9 | 6 | 6 | 18 | 6 | 6 | 5 |
ADD16 | 17 | 10 | 10 | 34 | 10 | 10 | 9 |
ADSU4 | 5 | 4 | 4 | 10 | 4 | 4 | 3 |
ADSU8 | 9 | 6 | 6 | 18 | 6 | 6 | 5 |
ADSU16 | 17 | 10 | 10 | 34 | 10 | 10 | 9 |
AND2 | 1 | - | - | 1 | - | - | 1 |
AND3 | 1 | - | - | 1 | - | - | 1 |
AND4 | 1 | - | - | 1 | - | - | 1 |
AND5 | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
AND6 | 2 | 1 | 1 | 2 | 1 | 1 | 1 |
AND7 | 2 | 1 | 1 | 3 | 1 | 1 | 1 |
AND8 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
AND9 | 2 | 1 | 1 | 4 | 1 | 1 | 2 |
AND12 | - | - | - | 4 | - | - | 2 |
AND16 | - | - | - | 5 | - | - | 2 |
BRLSHFT4 | 4 | 4 | 4 | 4 | 4 | 4 | 8 |
BRLSHFT8 | 12 | 12 | 12 | 12 | 12 | 12 | 12 |
BSCAN | - | - | - | 3 | - | - | - |
BUFE | 1 | - | - | - | - | - | - |
BUFE4 | 1 | - | - | - | - | - | - |
BUFE8 | 1 | - | - | - | - | - | - |
BUFE16 | 1 | - | - | - | - | - | - |
BUFG | 1 | - | - | 1 | - | - | - |
BUFGP | - | - | - | 1 | - | - | - |
BUFGS | - | - | - | 1 | - | - | - |
CB2CE | 3 | 2 | 2 | 4 | 2 | 2 | 2 |
CB2CLE | 4 | 3 | 3 | 5 | 3 | 3 | 3 |
CB2CLED | 4 | 3 | 3 | 6 | 3 | 3 | 3 |
CB2RE | 3 | 2 | 2 | 4 | 2 | 2 | 2 |
CB4CE | 4 | 3 | 3 | 6 | 3 | 3 | 3 |
CB4CLE | 7 | 5 | 5 | 9 | 5 | 5 | 5 |
CB4CLED | 8 | 7 | 7 | 10 | 7 | 7 | 6 |
CB4RE | 4 | 4 | 4 | 8 | 4 | 4 | 3 |
CB8CE | 8 | 6 | 6 | 13 | 6 | 6 | 6 |
CB8CLE | 13 | 10 | 10 | 18 | 10 | 10 | 9 |
CB8CLED | 14 | 12 | 13 | 22 | 12 | 13 | 12 |
CB8RE | 9 | 8 | 8 | 17 | 8 | 8 | 6 |
CB16CE | 16 | 12 | 12 | 27 | 12 | 12 | 13 |
CB16CLE | 26 | 18 | 18 | 36 | 18 | 18 | 18 |
CB16CLED | 28 | 25 | 25 | 46 | 25 | 25 | 24 |
CB16RE | 18 | 18 | 18 | 35 | 18 | 18 | 13 |
CC8CE | - | 5 | 5 | 18 | 5 | 5 | 8 |
CC8CLE | - | 6 | 6 | 19 | 6 | 6 | 9 |
CC8CLED | - | 11 | 11 | 19 | 11 | 11 | 9 |
CC8RE | - | 5 | 5 | 18 | 5 | 5 | 9 |
CC16CE | - | 9 | 9 | 34 | 9 | 9 | 16 |
CC16CLE | - | 10 | 10 | 35 | 10 | 10 | 17 |
CC16CLED | - | 19 | 19 | 35 | 19 | 19 | 17 |
CC16RE | - | 9 | 9 | 34 | 9 | 9 | 17 |
CD4CE | 4 | 3 | 3 | 6 | 3 | 3 | 3 |
CD4CLE | 7 | 5 | 5 | 10 | 5 | 5 | 5 |
CD4RE | 5 | 6 | 5 | 9 | 6 | 5 | 3 |
CD4RLE | 10 | 9 | 9 | 17 | 9 | 9 | 7 |
CJ4CE | 2 | 2 | 2 | 4 | 2 | 2 | 2 |
CJ4RE | 2 | 4 | 4 | 4 | 4 | 4 | 2 |
CJ5CE | 3 | 3 | 3 | 5 | 3 | 3 | 3 |
CJ5RE | 3 | 5 | 5 | 5 | 5 | 5 | 3 |
CJ8CE | 4 | 4 | 4 | 8 | 4 | 4 | 4 |
CJ8RE | 4 | 8 | 8 | 8 | 8 | 8 | 4 |
COMP2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
COMP4 | 4 | 1 | 1 | 3 | 1 | 1 | 2 |
COMP8 | 9 | 4 | 4 | 5 | 4 | 4 | 3 |
COMP16 | 17 | 9 | 9 | 11 | 9 | 9 | 6 |
COMPM2 | 3 | 1 | 1 | 5 | 1 | 1 | 1 |
COMPM4 | 8 | 2 | 2 | 13 | 2 | 2 | 5 |
COMPM8 | 19 | 8 | 8 | 27 | 8 | 8 | 11 |
COMPM16 | 39 | 21 | 21 | 64 | 21 | 21 | 24 |
COMPMC8 | - | 7 | 7 | 18 | 7 | 7 | 8 |
COMPMC16 | - | 11 | 11 | 34 | 11 | 11 | 16 |
CR8CE | 8 | 8 | 8 | 8 | 8 | 8 | 8 |
CR16CE | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
CY_INIT | - | - | - | 1 | - | - | - |
CY_MUX | - | - | - | 2 | - | - | - |
D2_4E | 2 | 2 | 2 | 4 | 2 | 2 | 2 |
D3_8E | 4 | 4 | 4 | 8 | 4 | 4 | 4 |
D4_16E | 16 | 16 | 16 | 32 | 16 | 16 | 16 |
DEC_CC4 | - | - | - | 2 | - | - | 1 |
DEC_CC8 | - | - | - | 3 | - | - | 1 |
DEC_CC16 | - | - | - | 5 | - | - | 2 |
DECODE4 | - | - | - | 2 | - | - | 1 |
DECODE8 | - | - | - | 3 | - | - | 2 |
DECODE16 | - | - | - | 5 | - | - | 2 |
DECODE32 | - | - | - | 9 | - | - | 4 |
DECODE64 | - | - | - | 18 | - | - | 8 |
F5_MUX | - | - | - | 1 | - | - | - |
F5MAP | - | - | - | 1 | - | - | - |
FD | 1 | - | - | 1 | - | - | - |
FD_1 | 1 | - | - | 1 | - | - | - |
FD4CE | 4 | 2 | 2 | 4 | 2 | 2 | 2 |
FD4RE | 2 | 4 | 4 | 4 | 4 | 4 | 2 |
FD8CE | 4 | 4 | 4 | 8 | 4 | 4 | 4 |
FD8RE | 4 | 8 | 8 | 8 | 8 | 8 | 4 |
FD16CE | 8 | 8 | 8 | 16 | 8 | 8 | 8 |
FD16RE | 8 | 16 | 16 | 16 | 16 | 16 | 8 |
FDC | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDC_1 | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDCE | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDCE_1 | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDP | - | 1 | 1 | 1 | 1 | 1 | - |
FDP_1 | - | 1 | 1 | 1 | 1 | 1 | - |
FDPE | - | - | - | 1 | - | - | - |
FDPE_1 | - | 1 | 1 | 1 | 1 | 1 | - |
FDR | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDRE | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDRS | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDRSE | 1 | 2 | 2 | 3 | 2 | 2 | - |
FDS | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDSE | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDSR | 1 | 1 | 1 | 1 | 1 | 1 | - |
FDSRE | 1 | 2 | 2 | 3 | 2 | 2 | - |
FJKC | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
FJKCE | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
FJKP | - | 1 | 1 | 1 | 1 | 1 | 1 |
FJKPE | - | 1 | 1 | 1 | 1 | 1 | 1 |
FJKRSE | 2 | 2 | 2 | 3 | 2 | 2 | 1 |
FJKSRE | 2 | 2 | 2 | 3 | 2 | 2 | 1 |
FTC | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
FTCE | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
FTCLE | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
FTCLEX | - | - | - | - | - | - | 1 |
FTP | - | 1 | 1 | 1 | 1 | 1 | 1 |
FTPE | - | 1 | 1 | 1 | 1 | 1 | 1 |
FTPLE | - | 1 | 1 | 2 | 1 | 1 | 1 |
FTRSE | 1 | 2 | 2 | 3 | 2 | 2 | 1 |
FTRSLE | 3 | 2 | 2 | 4 | 2 | 2 | 2 |
FTSRE | 1 | 2 | 2 | 3 | 2 | 2 | 1 |
FTSRLE | 3 | 2 | 2 | 4 | 2 | 2 | 2 |
GCLK | 1 | - | - | - | - | - | - |
IFD | - | - | - | 1 | - | - | - |
IFD_1 | - | - | - | 1 | - | - | - |
IFD4 | - | - | - | 4 | - | - | - |
IFD8 | - | - | - | 8 | - | - | - |
IFD16 | - | - | - | 16 | - | - | - |
ILD | - | - | - | 1 | - | - | 1 |
ILD_1 | - | - | - | 1 | - | - | 1 |
ILD4 | - | - | - | 4 | - | - | 2 |
ILD8 | - | - | - | 8 | - | - | 4 |
ILD16 | - | - | - | 16 | - | - | 8 |
IOPAD | - | - | - | 1 | - | - | - |
LD | - | - | 1 | 1 | - | 1 | - |
LD4 | - | - | 4 | - | - | 4 | 2 |
LD8 | - | - | 8 | - | - | 8 | 4 |
LD16 | - | - | 16 | - | - | 16 | 8 |
LD4CE | - | - | 4 | 4 | - | 4 | 2 |
LD8CE | - | - | 8 | 8 | - | 8 | 4 |
LD16CE | - | - | 16 | 16 | - | 16 | 8 |
LD_1 | - | - | 1 | 1 | - | 1 | - |
LDC | - | - | 1 | 1 | - | 1 | - |
LDC_1 | - | - | 1 | 1 | - | 1 | - |
LDCE | - | - | 1 | 1 | - | 1 | - |
LDCE_1 | - | - | - | 1 | - | - | - |
LDPE | - | - | 1 | - | - | 1 | - |
LDPE_1 | - | - | 1 | - | - | 1 | - |
M2_1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
M2_1B1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
M2_1B2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
M2_1E | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
M4_1E | 3 | 1 | 1 | 1 | 1 | 1 | 1 |
M8_1E | 6 | 3 | 3 | 7 | 3 | 3 | 2 |
M16_1E | 11 | 7 | 7 | 14 | 7 | 7 | 5 |
NAND2 | 1 | - | - | 1 | - | - | 1 |
NAND3 | 1 | - | - | 1 | - | - | 1 |
NAND4 | 1 | - | - | 1 | - | - | 1 |
NAND5 | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
NAND6 | 2 | 1 | 1 | 2 | 1 | 1 | 1 |
NAND7 | 2 | 1 | 1 | 3 | 1 | 1 | 1 |
NAND8 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
NAND9 | 2 | 1 | 1 | 4 | 1 | 1 | 2 |
NAND12 | - | - | - | 4 | - | - | 2 |
NAND16 | - | - | - | 5 | - | - | 2 |
NOR2 | 1 | - | - | 1 | - | - | 1 |
NOR3 | 1 | - | - | 1 | - | - | 1 |
NOR4 | 1 | - | - | 1 | - | - | 1 |
NOR5 | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
NOR6 | 2 | 1 | 1 | 2 | 1 | 1 | 1 |
NOR7 | 2 | 1 | 1 | 3 | 1 | 1 | 1 |
NOR8 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
NOR9 | 2 | 1 | 1 | 4 | 1 | 1 | 2 |
NOR12 | - | - | - | 4 | - | - | 2 |
NOR16 | - | - | - | 5 | - | - | 2 |
OFD | - | - | - | 1 | - | - | - |
OFD_1 | - | - | - | 1 | - | - | - |
OFD4 | - | - | - | 4 | - | - | - |
OFD8 | - | - | - | 8 | - | - | - |
OFD16 | - | - | - | 16 | - | - | - |
OFDE | - | - | - | 1 | - | - | - |
OFDE_1 | - | - | - | 1 | - | - | - |
OFDE4 | - | - | - | 4 | - | - | - |
OFDE8 | - | - | - | 8 | - | - | - |
OFDE16 | - | - | - | 16 | - | - | - |
OFDT | - | - | - | 1 | - | - | - |
OFDT_1 | - | - | - | 1 | - | - | - |
OFDT4 | - | - | - | 4 | - | - | - |
OFDT8 | - | - | - | 8 | - | - | - |
OFDT16 | - | - | - | 16 | - | - | - |
OR2 | 1 | - | - | 1 | - | - | 1 |
OR3 | 1 | - | - | 1 | - | - | 1 |
OR4 | 1 | - | - | 1 | - | - | 1 |
OR5 | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
OR6 | 2 | 1 | 1 | 2 | 1 | 1 | 1 |
OR7 | 2 | 1 | 1 | 3 | 1 | 1 | 1 |
OR8 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
OR9 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
OR12 | - | - | - | 4 | - | - | 2 |
OR16 | - | - | - | 5 | - | - | 2 |
RAM16X2 | - | 1 | 1 | - | 1 | 1 | - |
RAM16X2D | - | 2 | 2 | - | 2 | 2 | 2 |
RAM16X2S | - | 1 | 1 | - | 1 | 1 | 2 |
RAM16X4 | - | 2 | 2 | - | 2 | 2 | - |
RAM16X4D | - | 4 | 4 | - | 4 | 4 | 4 |
RAM16X4S | - | 2 | 2 | - | 2 | 2 | 4 |
RAM16X8 | - | 4 | 4 | - | 4 | 4 | - |
RAM16X8D | - | 8 | 8 | - | 8 | 8 | 8 |
RAM16X8S | - | 4 | 4 | - | 4 | 4 | 8 |
RAM32X2 | - | 2 | 2 | - | 2 | 2 | - |
RAM32X2S | - | 2 | - | - | 2 | - | 2 |
RAM32X4 | - | 4 | 4 | - | 4 | 4 | 4 |
RAM32X4S | - | 4 | 4 | - | 4 | 4 | 8 |
RAM32X8 | - | 8 | 8 | - | 8 | 8 | - |
RAM32X8S | - | 8 | 8 | - | 8 | 8 | - |
SOP3 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
SOP4 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
SR4CE | 2 | 2 | 2 | 4 | 2 | 2 | 2 |
SR4CLE | 4 | 3 | 3 | 5 | 3 | 3 | 3 |
SR4CLED | 5 | 5 | 5 | 10 | 5 | 5 | 5 |
SR4RE | 2 | 4 | 4 | 4 | 4 | 4 | 2 |
SR4RLE | 6 | 5 | 5 | 9 | 5 | 5 | 3 |
SR4RLED | 7 | 8 | 8 | 14 | 8 | 8 | 5 |
SR8CE | 4 | 4 | 4 | 8 | 4 | 4 | 4 |
SR8CLE | 5 | 5 | 5 | 9 | 5 | 5 | 5 |
SR8CLED | 9 | 9 | 9 | 18 | 9 | 9 | 9 |
SR8RE | 4 | 8 | 8 | 8 | 8 | 8 | 4 |
SR8RLE | 12 | 9 | 9 | 17 | 9 | 9 | 5 |
SR8RLED | 13 | 9 | 9 | 26 | 9 | 9 | 9 |
SR16CE | 8 | 8 | 8 | 16 | 8 | 8 | 8 |
SR16CLE | 9 | 9 | 9 | 17 | 9 | 9 | 9 |
SR16CLED | 17 | 17 | 17 | 34 | 17 | 17 | 17 |
SR16RE | 8 | 16 | 16 | 16 | 16 | 16 | 8 |
SR16RLE | 24 | 20 | 20 | 33 | 20 | 20 | 9 |
SR16RLED | 25 | 19 | 19 | 50 | 19 | 19 | 17 |
UPAD | - | - | - | 1 | - | - | - |
XNOR2 | 1 | - | - | 1 | - | - | 1 |
XNOR3 | 1 | - | - | 1 | - | - | 1 |
XNOR4 | 1 | - | - | 1 | - | - | 1 |
XNOR5 | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
XNOR6 | 2 | 1 | 1 | 2 | 1 | 1 | 1 |
XNOR7 | 2 | 1 | 1 | 3 | 1 | 1 | 1 |
XNOR8 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
XNOR9 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
XOR2 | 1 | - | - | 1 | - | - | 1 |
XOR3 | 1 | - | - | 1 | - | - | 1 |
XOR4 | 1 | - | - | 1 | - | - | 1 |
XOR5 | 1 | 1 | 1 | 2 | 1 | 1 | 1 |
XOR6 | 2 | 1 | 1 | 2 | 1 | 1 | 1 |
XOR7 | 2 | 1 | 1 | 3 | 1 | 1 | 1 |
XOR8 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
XOR9 | 2 | 1 | 1 | 3 | 1 | 1 | 2 |
X74_42 | 5 | 5 | 5 | 10 | 5 | 5 | - |
X74_L85 | 14 | 9 | 9 | 20 | 9 | 9 | - |
X74_138 | 5 | 5 | 5 | 9 | 5 | 5 | - |
X74_139 | 2 | 2 | 2 | 4 | 2 | 2 | - |
X74_147 | 8 | 6 | 6 | 12 | 6 | 6 | - |
X74_148 | 10 | 6 | 6 | 14 | 6 | 6 | - |
X74_150 | 11 | 6 | 6 | 13 | 6 | 6 | - |
X74_151 | 6 | 3 | 3 | 7 | 3 | 3 | - |
X74_152 | 5 | 3 | 3 | 6 | 3 | 3 | - |
X74_153 | 6 | 3 | 3 | 6 | 3 | 3 | - |
X74_154 | 17 | 16 | 16 | 33 | 16 | 16 | - |
X74_157 | 4 | 2 | 2 | 4 | 2 | 2 | - |
X74_158 | 4 | 2 | 2 | 4 | 2 | 2 | - |
X74_160 | 8 | 6 | 6 | 11 | 6 | 6 | - |
X74_161 | 9 | 5 | 5 | 9 | 5 | 5 | - |
X74_162 | 8 | 6 | 6 | 13 | 6 | 6 | - |
X74_163 | 10 | 9 | 9 | 17 | 9 | 9 | - |
X74_164 | 5 | 4 | 4 | 8 | 4 | 4 | - |
X74_165S | 8 | 5 | 5 | 9 | 5 | 5 | - |
X74_168 | 9 | 7 | 7 | 11 | 7 | 7 | - |
X74_174 | 7 | 4 | 4 | 6 | 4 | 4 | - |
X74_194 | 7 | 5 | 5 | 12 | 5 | 5 | - |
X74_195 | 5 | 3 | 3 | 5 | 3 | 3 | - |
X74_273 | 9 | 5 | 5 | 8 | 5 | 5 | - |
X74_280 | 3 | 2 | 2 | 5 | 2 | 2 | - |
X74_283 | 4 | 6 | 6 | 8 | 6 | 6 | - |
X74_298 | 4 | 2 | 2 | 4 | 2 | 2 | - |
X74_352 | 6 | 3 | 3 | 6 | 3 | 3 | - |
X74_377 | 9 | 4 | 4 | 8 | 4 | 4 | - |
X74_390 | 3 | 3 | 3 | 4 | 3 | 3 | - |
X74_518 | 9 | 4 | 4 | 6 | 4 | 4 | - |
X74_521 | 9 | 4 | 4 | 6 | 4 | 4 | - |
*LC4 count **Combined count for the two Virtex slices - = zero (0) or the component is not applicable for that architecture |