Chapter 12. Test
12-13
Test Wrapper
Figure 12-10. CF4e Core to CF4eTW Output Scan Delay Vector Example
When a hard-layout-core is delivered, understanding this operation is unnecessary because
vectors exist for these operations (for example, the CF4e core manufacturing test program).
12.2.4.3 CF4eTW Testing of Noncore Inputs
The CF4eTW is designed as a standalone device; it does not need CF4e core scan
architecture for all testing. A gate-level netlist of the CF4eTW can be included as part of
the noncore logic netlist when vector generation is to be done.
Wrapper scan launch mode uses the CF4eTW’s ability to launch single logic values or
vector pair logic transition values into the noncore logic. This testing uses tbseo, which
enables the CF4eTW scan architecture to either shift data through the CF4eTW output side
scan chains (launching data into the noncore logic) or to capture data from the CF4e core
clkfast
tbsei
Last Scan Shift In
First Scan Shift Out
1st Functional
Sample
registered
CF4eTW
Input
Data
Register Setup
Time Point
for CF4eTW
boundary scan
tbseo
Data
Data
output
CF4eTW
functional
register
Data
Data
Data
Note: No Sample
Needs to be done
by the CF4eTW inputs
Capture Point
for Transition Effect
into CF4eTW Scan Cell
tbte
Outputs to non-core
logic not considered
in this example
Establish
Fault Exercise
Values into
CF4e logic
se
Original
State
2nd Functional
Sample
Data
Transition
State
Data
Path
F
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