ADIS16448SLASHPCBZ datasheet(18/24 Pages) AD

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ADIS16448

Data Sheet

Rev. B | Page 18 of 24

MAGNETOMETER/BAROMETER

The magnetometer (xMAGN_OUT) and barometer output

registers (BARO_OUT) update at a rate of 51.2 SPS. When

using the external clock, these registers update at a rate of 1/16th

of the input clock frequency. The update rates for the magne-

tometer and barometers do not change with the SMPL_PRD

[15:8] register settings, unless SMPL_PRD[15:8] > 0x04.

New-Data Indicators

DIAG_STAT[7] (see Table 31) offers a new data bit for the

magnetometer (xMAGN_OUT) and barometer output registers

(BARO_OUT) registers. This bit rises to a 1, right after the

xMAGN_OUT and BARO_OUT registers receive fresh data.

It returns to 0 after one of the four registers experiences a

read request.

The SEQ_CNT register (see Table 36) provides a counter

function to help determine when there is new data in the

magnetometer and barometer registers. When using the full

sample rate (SMPL_PRD[15:8] = 0x00), SEQ_CNT will start

at a value of 16 and decrement every time the gyroscope data

updates. When it reaches a value of 1, it will return to a value

16 after the next gyroscope update cycle. When SEQ_CNT

equals 16, the magnetometer (xMAGN_OUT) and barometer

(BARO_OUT) registers contain new data. The SEQ_CNT

read loops for new data in both magnetometer and barometer

outputs. When beginning a continuous read loop, read SEQ_CNT

to determine the number of sample cycles that must pass, before

the magnetometer and barometer registers update.

Table 36. SEQ_CNT (Base Address = 0x3A), Read Only

Bits

Description

[15:11]

Don’t care

[6:0]

Binary counter: 16 to 1, when D = 0

Counter range = 16/2D – 1, when 1 ≤ D ≤ 4

See Table 34 for more information on D

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