Note
Calling a special function OB using the "JU OB 131/132/133" or
"JC OB 131/132/133" operation does not have the same effect as
a "genuine" block change, but functions as a STEP 5 operation
without block operand. No interrupts are nested (with the default
"interrupts at block boundaries").
Introduction
CPU 948 Programming Guide
C79000-G8576-C848-04
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