AX500-1BG896 ACTEL [Actel Corporation], AX500-1BG896 Datasheet - Page 57

• Manufacturer Part Number: AX500-1BG896
• Description: Axcelerator Family FPGAs
• Manufacturer: ACTEL [Actel Corporation]

Module Specifications
C-Cell
Introduction
The C-cell is one of the two logic module types in the AX
architecture. It is the combinatorial logic resource in the
Axcelerator device. The AX architecture implements a
new combinatorial cell that is an extension of the C-cell
implemented in the SX-A family. The main enhancement
of the new C-cell is the addition of carry-chain logic.
The C-cell can be used in a carry-chain mode to construct
arithmetic functions. If carry-chain logic is not required,
it can be disabled.
The C-cell features the following
Figure 2-27 • C-Cell
• Eight-input MUX (data: D0-D3, select: A0, A1, B0,
• Inverter (DB input) can be used to drive a
B1). User signals can be routed to any one of these
inputs. Any of the C-cell inputs (D0-D3, A0, A1, B0,
B1) can be tied to one of the four routed clocks
(CLKE/F/G/H).
complement signal of any of the inputs to the C-
cell.
D0 D2
D1 D3
(Figure
B0
B1
2-27):
DB
0
1
0
1
A0
0
A1
0
1
1
v2.7
This layout of the C-cell (and the C-cell Cluster) enables
the implementation of over 4,000 functions of up to five
bits. For example, two C-cells can be used together to
implement a four-input XOR function in a single cell
delay.
The carry-chain configuration is handled automatically
for the user with Actel's extensive macro library (please
see Actel’s
listing of available Axcelerator macros).
.
• A carry input and a carry output. The carry input
• Carry connect for carry-chain logic with a signal
• A hardwired connection (direct connect) to the
CFN FCI
signal of the C-cell is the carry output from the C-
cell directly to the north.
propagation time of less than 0.1 ns.
adjacent R-cell (Register Cell) for all C-cells on the
east side of a SuperCluster with a signal
propagation time of less than 0.1 ns.
Antifuse Macro Library Guide
0
1
FCO
Y
Axcelerator Family FPGAs
for a complete
2-43