4.4

Mapping the TDM axes

Within one frame, the data signal (DOUT) is divided into multiple segments. We call each segment a slot hereafter

in this document.

The data slot width is fixed and equal to 16 bits.

In each slot, data should be left-justified (MSB first).

The number of slots in a WCLK frame can be variable, and it depends on the ratio between BCLK and

WCLK. However, as depicted in Table 9 and Table 10, only the slots 0, 1, 2 and 4, 5, 6 can be used to send

accelerometer data, all the others slots are always set in high-impedance.

The mapping of the input data and the TDM output slots is flexible and can be configured through the I²C register

mapping (TDM_CTRL_REG (2Eh) bit 4) in Figure 4.

In particular two possible configurations can be selected:

•

Axes data (X,Y,Z) mapped on TDM slots (0,1,2) (mapping = 0)

•

Axes data (X,Y,Z) mapped on TDM slots (4,5,6) (mapping = 1)

SLOT0

SLOT1

SLOT2

SLOT3

SLOT4

SLOT5

SLOT6

SLOT7

...

SLOTN

X-axis

Y-axis

Z-axis

HiZ

HiZ

HiZ

HiZ

HiZ

HiZ

SLOT0

SLOT1

SLOT2

SLOT3

SLOT4

SLOT5

SLOT6

SLOT7

...

SLOTN

HiZ

HiZ

HiZ

HiZ

X-axis

Y-axis

Z-axis

HiZ

HiZ

AIS25BA

Mapping the TDM axes

DS14019 - Rev 1

page 11/31