XC9500 Xilinx Corp., XC9500 Datasheet - Page 6

• Manufacturer Part Number: XC9500
• Description: XC9500 5 V CPLD Family
• Manufacturer: Xilinx Corp.

XC9500 In-System Programmable CPLD Family
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
6
Figure 5: Macrocell Logic Using Direct Product Term
5.
Product Term
Allocator
PTA,
as shown in
Macrocell
Product Term
Logic
DS063_05_110501
Figure
6.
www.xilinx.com
1-800-255-7778
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
Product Term
Allocator
Product Term
Product Term
Allocator
Allocator
Terms
DS063 (v5.1) September 22, 2003
Product Specification
Macrocell Logic
With 15
Product Terms
DS063_06_110501
R