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Home > MBIST Instruction Register > Field descriptions > Control field, MBIR[39:34] |
The control field specifies the MBIST function. Table 3.9 shows how the control field affects the behavior of the ARM L210 MBIST Controller.
Table 3.9. Control field encoding
Control MBIR[39:34] | Behavior | Description |
---|---|---|
bx00000 | Default | Test runs to completion. If MBIR[39] = 0, sticky fail present after first failure. |
bx00001 | Stop on fail | End of test on failure. |
bx00011 | Bitmap mode | Enables logging of each failure. See Bitmap mode. |
MBIR[39] selects a nonsticky or sticky fail flag, MBISTRESULT[1]:
When MBIR[39] is set, the fail bit toggles in real time. It goes HIGH for failing comparisons and LOW for passing comparisons.
Setting MBIR[39] can cause the fail bit to toggle at the test frequency. It is not recommended when the external pin or the ATE cannot follow the test frequency.
When MBIR[39] is cleared, the fail bit is sticky. It remains HIGH after the first failure until a new MBIST instruction shifts in or until the data log shifts out.