Sensors

19

Freescale Semiconductor, Inc.

MMA7660FC

AMSR[2:0]

NAME

DESCRIPTION

000

AMPD

Tap Detection Mode and 120 Samples/Second Active and Auto-Sleep Mode

Tap Detection Sampling Rate: The device takes readings continually at a rate of nominally 3846 g-cell

measurements a second. It then filters these high speed measurements by maintaining continuous rolling averages of

the current and last g-cell measurements. The averages are updated every 260 µs to track fast moving accelerations.

Tap detection: itself compares the two filtered axis responses (fast and slow) described above for each axis. The

absolute (unsigned) difference between the fast and slow axis responses is compared against the tap detection delta

threshold value PDTH[4:0] in the PDET (0x09) register.

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 8.36 ms in Active

Mode and Auto-Sleep. The update rate is 120 samples per second. These measurements update the XOUT (0x00),

YOUT (0x01), and ZOUT (0x02) registers also.

001

AM64

64 Samples/Second Active and Auto-Sleep Mode

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every

15.625 ms in Active Mode and Auto-Sleep. The update rate is 64 samples per second. These measurements update

the XOUT (0x00), YOUT (0x01), and ZOUT (0x02) registers also.

010

AM32

32 Samples/Second Active and Auto-Sleep Mode

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 31.25 ms in Active

Mode and Auto-Sleep. The update rate is 32 samples per second. These measurements update XOUT (0x00), YOUT

(0x01), and ZOUT (0x02) registers also.

011

AM16

16 Samples/Second Active and Auto-Sleep Mode

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 62.5 ms in Active

Mode and Auto-Sleep. The update rate is 16 samples per second. These measurements update the XOUT (0x00),

YOUT (0x01), and ZOUT (0x02) registers also.

100

AM8

8 Samples/Second Active and Auto-Sleep Mode

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 125 ms in Active

Mode and Auto-Sleep. The update rate is 8 samples per second. These measurements update the XOUT (0x00),

YOUT (0x01), and ZOUT (0x02) registers also.

101

AM4

4 Samples/Second Active and Auto-Sleep Mode

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 250 ms in Active

Mode and Auto-Sleep. The update rate is 4 samples per second. These measurements update the XOUT (0x00),

YOUT (0x01), and ZOUT (0x02) registers also.

110

AM2

2 Samples/Second Active and Auto-Sleep Mode

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 500 ms in Active

Mode and Auto-Sleep. The update rate is 2 samples per second. These measurements update the XOUT (0x00),

YOUT (0x01), and ZOUT (0x02) registers also.

111

AM1

1 Sample/Second Active and Auto-Sleep Mode

For portrait/landscape detection: The device takes and averages 32 g-cell measurements every 1000 ms in Active

Mode and Auto-Sleep. The update rate is 1 sample per second. These measurements update the XOUT (0x00), YOUT

(0x01), and ZOUT (0x02) registers also.