Sensors

21

Freescale Semiconductor, Inc.

MMA7660FC

$09: Tap/Pulse Detection Register (Read/Write)

PDET

NOTE: If XDA = YDA = ZDA = 0, samples per second is 120 samples/second, and Auto-Wake/Sleep feature is enabled,

the tap interrupt will reset the sleep counter.

XDA

1: X-axis is disabled for tap detection

0: X-axis is enabled for tap detection

YDA

1: Y-axis is disabled for tap detection

0: Y-axis is enabled for tap detection

ZDA

1: Z-axis is disabled for tap detection

0: Z-axis is enabled for tap detection

$0A: PD: Tap/Pulse Debounce Count Register (Read/Write)

D7

D6

D5

D4

D3

D2

D1

D0

ZDA

YDA

XDA

PDTH[4]

PDTH[3]

PDTH[2]

PDTH[1]

PDTH[0]

0

0

0

000

00

PDTH[4:0]

DESCRIPTION

00000

Tap detection threshold is ±1 count

00001

00010

Tap detection threshold is ±2 counts

00011

Tap detection threshold is ±3 counts

...

... and so on up to...

11101

Tap detection threshold is ±29 counts

11110

Tap detection threshold is ±30 counts

11111

Tap detection threshold is ±31 counts

D7

D6

D5

D4

D3

D2

D1

D0

PD[7]

PD[6]

PD[5]

PD[4]

PD[3]

PD[2]

PD[1]

PD[0]

0

000000

0

PD[4:0]

DESCRIPTION

00000000

The tap detection debounce filtering requires 2 adjacent tap detection tests to be the same to trigger a tap event and set the

Tap bit in the TILT (0x03) register, and optionally set an interrupt if PDINT is set in the INTSU (0x06) register. Tap detection

response time is nominally 0.52 ms.

00000001

00000010

Tap detection debounce filtering requires 3 adjacent tap detection tests to be the same to trigger a tap event and set the Tap

bit in the TILT (0x03) register, and optionally set an interrupt if PDINT is set in the INTSU (0x06) register. Tap detection

response time is nominally 0.78 ms.

00000011

Tap detection debounce filtering requires 4 adjacent tap detection tests to be the same to trigger a tap event and set the Tap

bit in the TILT (0x03) register, and optionally set an interrupt if PDINT is set in the INTSU (0x06) register. Tap detection

response time is nominally 1.04 ms.

...

... and so on up to...

11111101

Tap detection debounce filtering requires 254 adjacent tap detection tests to be the same to trigger a tap event and set the

Tap bit in the TILT (0x03) register, and optionally set an interrupt if PDINT is set in the INTSU (0x06) register. Tap detection

response time is nominally 66.04 ms.

11111110

Tap detection debounce filtering requires 255 adjacent tap detection tests to be the same to trigger a tap event and set the

Tap bit in the TILT (0x03) register, and optionally set an interrupt if PDINT is set in the INTSU (0x06) register. Tap detection

response time is nominally 66.3 ms.

11111111

Tap detection debounce filtering requires 256 adjacent tap detection tests to be the same to trigger a tap event and set the

Tap bit in the TILT (0x03) register, and optionally set an interrupt if PDINT is set in the INTSU (0x06) register. Tap detection

response time is nominally 66.56 ms.