AN2989

Interrupt generation

Doc ID 15761 Rev 1

25/28

XL bits of INTx_SRC send information about the value of the acceleration generating the

interrupt when it exceeds the threshold, and whether the acceleration value is positive or

negative. More specifically:

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ZH (YH, XH) is 1 when the sensed acceleration is greater than the threshold in the

positive direction.

●

ZL (YL, XL) is 1 when the sensed acceleration is greater than the threshold in the

negative direction.

Figure 12.

ZH, ZL, YH, YL, XH, XL behavior

There are two possible configurations for the 6D direction function:

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6D movement recognition: In this configuration the interrupt is generated when the

device moves from one direction (known or unknown) to a different, known direction.

The interrupt is active only for 1/ODR.

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6D position recognition: In this configuration the interrupt is generated when the

device is stable in a known direction. The interrupt is active as long as the position is

maintained, as shown in Figure 13, (a) and (b).

In Figure 13, the 6D Movement line shows the behavior of the interrupt when the device is

configured for 6D Movement recognition on the X and Y axes (INT1_CFG = 0x4Ah), while

the 6D Position line shows the behavior of the interrupt when the device is configured for 6D

Position recognition on the X and Y axes (INT1_CFG = 0xCAh). INT1_THS is set to 0x21.

With reference to Figure 14, the device has been configured for the 6D Position function on

the X, Y and Z axes.Table 19 shows the content of the INT1_SRC register for each position.

Figure 13.

6D movement vs. 6D position