Sensors

15

Freescale Semiconductor, Inc.

MMA7660FC

$03: Tilt Status (Read only)

TILT

BaFro[1:0]

00:Unknown condition of front or back

01: Front: Equipment is lying on its front

10: Back: Equipment is lying on its back

PoLa[2:0]

000: Unknown condition of up or down or left or right

001: Left: Equipment is in landscape mode to the left

010: Right: Equipment is in landscape mode to the right

101: Down: Equipment standing vertically in inverted

orientation

110: Up: Equipment standing vertically in normal orientation

Tap

1: Equipment has detected a tap

0: Equipment has not detected a tap

Alert

0: Register data is valid

1: The register was read at the same time as MMA7660FC

was attempting to update the contents. Re-read the register

Shake

0: Equipment is not experiencing shake in one or more of the

axes enabled by SHINTX, SHINTY, and SHINTZ

1: Equipment is experiencing shake in one or more of the

axes enabled by SHINTX, SHINTY, and SHINTZ

Note: When entering active mode from standby mode, if the device is flat (±1g on Z-axis) the value for BaFro will be back (-1g)

or front (+1g) but PoLa will be in unknown condition. if the device is being held in an Up/Down/Right/Left position, the PoLa value

will be updated with current orientation, but BaFro will be in unknown condition.

$04: Sample Rate Status Register (Read only)

SRST

AMSRS

0: Samples per second specified in AMSR[2:0] is not active

1: Samples per second specified in AMSR[2:0] is active

AWSRS

0: Samples per second specified in AWSR[1:0] is not active

1: Samples per second specified in AWSR[1:0] is active

$05: Sleep Count Register (Read/Write)

SPCNT

Writing to the SPCNT (0x05) register resets the internal sleep counter.

SC[7:0]

Sets the 8-bit maximum count value for the 8-bit internal sleep counter in Auto-Sleep. When the 8-bit internal sleep counter

reaches the value set by SC[7:0], MMA7660FC will exit Auto-Sleep and switch to the samples per second specified in AWSR[1:0]

of the SR (0x08) register.

D7

D6

D5

D4

D3

D2

D1

D0

Shake

Alert

Tap

PoLa[2]

PoLa[1]

PoLa[0]

BaFro[1]

BaFro[0]

000000

0

0

D7

D6

D5

D4

D3

D2

D1

D0

00

0000

AWSRS

AMSRS

00

0000

00

D7

D6

D5

D4

D3

D2

D1

D0

SC[7]SC[6]SC[5]SC[4]SC[3]SC[2]

SC[1]SC[0]

0

000

0000