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EPM240 Datasheet, PDF (12/86 Pages) Altera Corporation – JTAG & In-System Programmability | |||
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2â4
Chapter 2: MAX II Architecture
Logic Array Blocks
Logic Array Blocks
Each LAB consists of 10 LEs, LE carry chains, LAB control signals, a local interconnect,
a look-up table (LUT) chain, and register chain connection lines. There are 26 possible
unique inputs into an LAB, with an additional 10 local feedback input lines fed by LE
outputs in the same LAB. The local interconnect transfers signals between LEs in the
same LAB. LUT chain connections transfer the output of one LEâs LUT to the adjacent
LE for fast sequential LUT connections within the same LAB. Register chain
connections transfer the output of one LEâs register to the adjacent LEâs register
within an LAB. The Quartus® II software places associated logic within an LAB or
adjacent LABs, allowing the use of local, LUT chain, and register chain connections
for performance and area efficiency. Figure 2â3 shows the MAX II LAB.
Figure 2â3. MAX II LAB Structure
Row Interconnect
Fast I/O connection
to IOE (1)
DirectLink
interconnect from
adjacent LAB
or IOE
DirectLink
interconnect to
adjacent LAB
or IOE
LE0
LE1
LE2
LE3
LE4
LE5
LE6
LE7
LE8
LE9
Logic Element
LAB
Note to Figure 2â3:
(1) Only from LABs adjacent to IOEs.
Local Interconnect
Column Interconnect
Fast I/O connection
to IOE (1)
DirectLink
interconnect from
adjacent LAB
or IOE
DirectLink
interconnect to
adjacent LAB
or IOE
LAB Interconnects
The LAB local interconnect can drive LEs within the same LAB. The LAB local
interconnect is driven by column and row interconnects and LE outputs within the
same LAB. Neighboring LABs, from the left and right, can also drive an LABâs local
interconnect through the DirectLink connection. The DirectLink connection feature
minimizes the use of row and column interconnects, providing higher performance
and flexibility. Each LE can drive 30 other LEs through fast local and DirectLink
interconnects. Figure 2â4 shows the DirectLink connection.
MAX II Device Handbook
© October 2008 Altera Corporation
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