EX128-CS100 datasheet(25/49 Pages) ACTEL

25 / 49 page

eX Family FPGAs

v4.3

1-21

Timing Characteristics

Timing characteristics for eX devices fall into three

categories: family-dependent, device-dependent, and

design-dependent.

The

input

and

output

buffer

characteristics are common to all eX family members.

Internal routing delays are device-dependent. Design

dependency means actual delays are not determined

until after placement and routing of the user’s design are

complete. Delay values may then be determined by using

the Timer utility or performing simulation with post-

layout delays.

Critical Nets and Typical Nets

Propagation delays are expressed only for typical nets,

which are used for initial design performance evaluation.

Critical net delays can then be applied to the most timing

critical paths. Critical nets are determined by net

property assignment prior to placement and routing. Up

to six percent of the nets in a design may be designated

as critical.

Long Tracks

Some nets in the design use long tracks. Long tracks are

special routing resources that span multiple rows,

columns, or modules. Long tracks employ three to five

antifuse connections. This increases capacitance and

resistance, resulting in longer net delays for macros

connected to long tracks. Typically, no more than six

percent of nets in a fully utilized device require long

tracks. Long tracks contribute approximately 4 ns to

8.4 ns

delay.

This

additional

delay

represented

statistically in higher fanout routing delays.

Timing Derating

eX devices are manufactured with a CMOS process.

Therefore, device performance varies according to

temperature, voltage, and process changes. Minimum

timing parameters reflect maximum operating voltage,

minimum

operating

temperature,

and

best-case

processing.

Maximum

timing

parameters

reflect

minimum

operating

voltage,

maximum

operating

temperature, and worst-case processing.

Temperature and Voltage Derating Factors

Table 1-16 • Temperature and Voltage Derating Factors

(Normalized to Worst-Case Commercial, TJ = 70°C, VCCA = 2.3V)

VCCA

Junction Temperature (TJ)

–55

–40

125

2.3

0.79

0.80

0.87

0.88

1.00

1.04

1.13

2.5

0.74

0.81

0.83

0.93

0.97

1.06

2.7

0.69

0.70

0.76

0.78

0.88

0.91

1.00

EX128-CS100 Datasheet(PDF) 25 Page - Actel Corporation

EX128-CS100 Datasheet(HTML) 25 Page - Actel Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

Datasheet Download

Link URL