Arria GX Architecture
to the two ALUTs, one ALM can implement various combinations of two
functions. This adaptability allows the ALM to be completely backward-
compatible with four-input LUT architectures. One ALM can also
implement any function of up to six inputs and certain seven-input
functions.
In addition to the adaptive LUT-based resources, each ALM contains two
programmable registers, two dedicated full adders, a carry chain, a
shared arithmetic chain, and a register chain. Through these dedicated
resources, the ALM can efficiently implement various arithmetic
functions and shift registers. Each ALM drives all types of interconnects:
local, row, column, carry chain, shared arithmetic chain, register chain,
and direct link interconnects. Figure 2–28 shows a high-level block
diagram of the Arria GX ALM while Figure 2–29 shows a detailed view
of all the connections in the ALM.
Figure 2–28. High-Level Block Diagram of the Arria GX ALM
carry_in
shared_arith_in
reg_chain_in
To general or
local routing
dataf0
datae0
dataa
datab
datac
To general or
local routing
adder0
D
Q
reg0
Combinational
Logic
datad
datae1
dataf1
To general or
local routing
adder1
D
Q
reg1
To general or
local routing
carry_out
shared_arith_out
reg_chain_out
Altera Corporation
May 2008
2–39
Arria GX Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
