EP1C3 ALTERA [Altera Corporation], EP1C3 Datasheet - Page 16

• Manufacturer Part Number: EP1C3
• Description: Cyclone FPGA Family
• Manufacturer: ALTERA [Altera Corporation]

Cyclone FPGA Family Data Sheet
Figure 8. Carry Select Chain
16
LAB Carry-In
A1
B1
A2
B2
A3
B3
A4
B4
A6
B6
A7
B7
A8
B8
A9
B9
A10
B10
A5
B5
LAB Carry-Out
0
0
LE1
LE2
LE3
LE4
LE5
LE6
LE7
LE8
LE9
LE10
1
1
Sum1
Sum2
Sum3
Sum4
Sum5
Sum6
Sum7
Sum8
Sum9
Sum10
The Quartus II Compiler automatically creates carry chain logic during
design processing, or the designer can create it manually during design
entry. Parameterized functions such as LPM functions automatically take
advantage of carry chains for the appropriate functions.
The Quartus II Compiler creates carry chains longer than 10 LEs by
linking LABs together automatically. For enhanced fitting, a long carry
chain runs vertically allowing fast horizontal connections to M4K
memory blocks. A carry chain can continue as far as a full column.
LAB Carry-In
Carry-In0
Carry-In1
data1
data2
Carry-Out0
LUT
LUT
LUT
LUT
Preliminary Information
Carry-Out1
Altera Corporation
Sum