XC9500 Xilinx Corp., XC9500 Datasheet - Page 13

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

Low Power Mode
All XC9500 devices offer a low-power mode for individual
macrocells or across all macrocells. This feature allows the
device power to be significantly reduced.
Each individual macrocell may be programmed in
low-power mode by the user. Performance-critical parts of
the application can remain in standard power mode, while
other parts of the application may be programmed for
low-power operation to reduce the overall power dissipation.
Macrocells programmed for low-power mode incur addi-
tional delay (T
register setup time. Product term clock to output and prod-
uct term output enable delays are unaffected by the macro-
cell power-setting.
Timing Model
The uniformity of the XC9500 architecture allows a simpli-
fied timing model for the entire device. The basic timing
DS063 (v5.1) September 22, 2003
Product Specification
Figure 13: In-System Programming Operation (a) Solder Device to PCB and (b) Program Using Download Cable
R
LP
) in pin-to-pin combinatorial delay as well as
(a)
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model, shown in
that use the direct product terms only, with standard power
setting, and standard slew rate setting.
each of the key timing parameters is affected by the product
term allocator (if needed), low-power setting, and slew-lim-
ited setting.
The product term allocation time depends on the logic span
of the macrocell function, which is defined as one less than
the maximum number of allocators in the product term path.
If only direct product terms are used, then the logic span is
0. The example in
terms are available with a span of 1. In the case of
the 18 product term function has a span of 2.
Detailed timing information may be derived from the full tim-
ing model shown in
for each parameter are given in the individual device data
sheets.
XC9500 In-System Programmable CPLD Family
Figure
Figure
Figure 6
(b)
14, is valid for macrocell functions
15. The values and explanations
shows that up to 15 product
X5902
Table 4
shows how
Figure
13
7,