Analog Devices ADXL180 iMEMS Manual page 37

ENTER SELF-TEST CYCLE
WAIT 32 SAMPLES
AVERAGE 64 SAMPLES
V
STZ1
ASSERT SELF-TEST SIGNAL
WAIT 32 SAMPLES
AVERAGE 64 SAMPLES
V
STP
DEASSERT
SELF-TEST SIGNAL
WAIT 32 SAMPLES
AVERAGE 64 SAMPLES
V
STZ2
OFFSET < V < OFFSET
MIN STZ1
YES
OFFSET < V < OFFSET
MIN STZ2
YES
Figure 27. First Half Is Joined to Second Half of ST Chain
NO
MAX
NO
MAX
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CALCULATE
STD = V – V
STP STZ1
NO
STD < STD < STD
MIN MAX
YES
CALCULATE
STZ = |V – V |
STZ1 STZ2
NO
STZ ≤ 4 LSB*
*10-BIT LSB
YES
INCREMENT PASS COUNT
INCREMENT CYCLE COUNT
YES
PASS COUNT = 2 ENTER PHASE 4
NO
NO
CYCLE COUNT = 6 ENTER SELF-TEST CYCLE
YES
SET SELF-TEST FAIL CODE
ENTER ERROR STATE
Figure 28. Internal Self-Test State Machine
ADXL180