DocID029694 Rev 1
3/11
TN1239
Programming of STCU2
11
1 Programming
of
STCU2
The normal flow to program STCU2 starts by providing the unlock keys and afterwards the
rest of the configuration (left side of
).
Unlock keys are static keys. The user can find their values in the STCU chapter of the
reference manual.
The STCU loads the configuration only if the user provides the correct unlock keys. If the
unlock keys are not correct, the STCU ignores the following configuration.
The user passes these values to the STCU by writing them into the UTest sector of the
Flash as DCF records as shown on the left side of
A problem occurs in case the user needs to change the STCU configuration. It means that
the user has programmed at least a pair of unlock keys into UTest.
Given that the STCU2 considers only the first valid unlock keys and the following
configuration, after the first acceptance of a configuration, STCU2 does not accept any other
settings even if the provided unlock keys are correct. The SSCM reads the DCF
incrementally from lower to higher addresses.
The right side of
shows two different configurations of the STCU. Both
configurations start with the correct unlock keys:
1.
First configuration starts at address X
2.
Second configuration starts at address Y
Even if the second configuration starts with the correct unlock keys, the STCU ignores it. As
a result, the STCU runs the L/MBIST accordingly with the configuration that starts at
address X.
Next section explains how to instruct the STCU to load the second configuration and discard
the first one.
Figure 1. STCU unlock keys organization
