XC9500XL Xilinx Corp., XC9500XL Datasheet - Page 7

• Manufacturer Part Number: XC9500XL
• Description: XC9500XL 3.3 V CPLD Family
• Manufacturer: Xilinx Corp.

Product Term Allocator
The product term allocator controls how the five direct prod-
uct terms are assigned to each macrocell. For example, all
five direct terms can drive the OR function as shown in
Figure
The product term allocator can re-assign other product
terms within the FB to increase the logic capacity of a mac-
rocell beyond five direct terms. Any macrocell requiring
additional product terms can access uncommitted product
terms in other macrocells within the FB. Up to 15 product
terms can be available to a single macrocell with only a
small incremental delay of t
DS054 (v1.6) January 24, 2002
Preliminary Product Specification
Figure 5: Macrocell Logic Using Direct Product Term
5.
R
Product Term
Allocator
PTA
,
as shown in
Macrocell
Product Term
Logic
Figure
DS054_05_042101
6.
www.xilinx.com
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Note that the incremental delay affects only the product
terms in other macrocells. The timing of the direct product
terms is not changed.
Figure 6: Product Term Allocation With 15 Product
XC9500XL High-Performance CPLD Family
Product Term
Allocator
Product Term
Product Term
Allocator
Allocator
Terms
Macrocell Logic
With 15
Product Terms
DS054_06_042101
7