RadTolerant FPGAs
v3.1
1-5
output track is dedicated to the output of a particular
module. Long segments are uncommitted and can be
assigned during routing. Each output segment spans
four channels (two above and two below), except near
the top and bottom of the array where edge effects
occur. Long vertical tracks contain either one or two
segments. An example of vertical routing tracks and
Antifuse Structures
An antifuse is a "normally open" structure as opposed to
the normally closed fuse structure used in PROMs
(programmable read-only memory) or PALs (programmed
array logic). The use of antifuses to implement a PLD
(programmable logic device) results in highly testable
structures, as well as efficient programming algorithms.
The structure is highly testable because there are no pre-
existing connections, enabling temporary connections to
be
made
using
pass
transistors.
These
temporary
connections can isolate individual antifuses to be
programmed, and also isolate individual circuit structures
to be tested. This can be done both before and after
programming. For example, all metal tracks can be tested
for continuity and shorts between adjacent tracks, and
the functionality of all logic modules can be verified.
Figure 1-5 Routing Structure
Vertical Routing Tracks
Segmented
Horizontal
Routing
Tracks
Logic
Modules
Antifuses
Table 1-1 Actel MIL-STD-883 Product Flow
Step
Screen
883 Method
883 - Class B
Requirement
1.
Internal Visual
2010, Test Condition B
100%
2.
Temperature Cycling
1010, Test Condition C
100%
3.
Constant Acceleration
2001, Test Condition D or E, Y1, Orientation Only
100%
4.
Seal
a. Fine
b. Gross
1014
100%
5.
Visual Inspection
2009
100%
6.
Pre-Burn-In Electrical Parameters
In accordance with applicable Actel device specification
100%
7.
Burn-in Test
1015, Condition D, 160 hours @ 125°C or 80 hours @ 150°C
100%
8.
Interim (Post-Burn-In) Electrical
Parameters
In accordance with applicable Actel device specification
100%
9.
Percent Defective Allowable
5%
All Lots
10.
Final Electrical Test
a. Static Tests
(1) 25°C (Subgroup 1, Table I)
(2) –55°C and +125°C
(Subgroups 2, 3, Table I)
b. Functional Tests
(1) 25°C (Subgroup 7, Table I)
(2) –55°C and +125°C
(Subgroups 8A and 8B, Table I)
c. Switching Tests at 25°C
(Subgroup 9, Table I)
In accordance with applicable Actel device specification, which
includes a, b, and c:
5005
100%
11.
External Visual
2009
100%
Note: When Destructive Physical Analysis (DPA) is performed on Class B devices, the step coverage requirement as specified in Method
2018 must be waived.