EPF10K200EBC600-3 Altera, EPF10K200EBC600-3 Datasheet - Page 19

• Manufacturer Part Number: EPF10K200EBC600-3
• Description: FLEX 10KE
• Manufacturer: Altera

Altera Corporation
Figure 9
with the carry chain. One portion of the LUT generates the sum of two bits
using the input signals and the carry-in signal; the sum is routed to the
output of the LE. The register can be bypassed for simple adders or used
for an accumulator function. Another portion of the LUT and the carry
chain logic generates the carry-out signal, which is routed directly to the
carry-in signal of the next-higher-order bit. The final carry-out signal is
routed to an LE, where it can be used as a general-purpose signal.
Figure 9. FLEX 10KE Carry Chain Operation (n-Bit Full Adder)
an
bn
a1
b1
a2
b2
Carry-In
shows how an n-bit full adder can be implemented in n + 1 LEs
FLEX 10KE Embedded Programmable Logic Devices Data Sheet
Carry Chain
Carry Chain
Carry Chain
Carry Chain
LUT
LUT
LUT
LUT
Register
Register
Register
Register
LEn + 1
LEn
LE1
LE2
sn
Carry-Out
s1
s2
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