ADIS16220

Preliminary Technical Data

Rev. PrE | Page 12 of 16

Manual Capture Mode

This is the factory-default mode, where the sensor waits for a

user-driven trigger to execute a data capture. Set GLOB_CMD[11]

= 1 (DIN = 0xBF08) to execute a data capture in this mode. Set

CAPT_CTRL[7:0] = 0x02 to place the device in manual mode

and enable the control bit that shuts the device down while it

waits for the data capture command.

Automatic Capture Mode

In automatic mode, the device executes data captures without

user input, on a periodic basis. Configuring the device for

this mode requires three steps: program the capture period

using CAPT_PRD, set the device in automatic mode using

CAPT_CTRL[3:2], and start the capture process/clock using

CLOB_CMD[11]. See Table 15 for an example of setting up

automatic mode.

Table 14. CAPT_PRD Register Bit Descriptions

Bit

Description (Default = 0x0000)

[15:10]

Not used

[9:8]

Scale

00 = 1 second/LSB

01 = 1 minute/LSB

10 = 1 hour/LSB

[7:0]

Data bits, binary format

Table 15. Example Event Mode Configuration Sequence

DIN

Description

0x9F02,

0x9E18

Set time scale to hours

Set the time between captures to 24 hours

0x9C06

Set the device for trigger mode and enable shutdown

0xBF08

Start: device executes a capture and shuts down

Event Capture Mode

The event capture mode triggers a data capture when the data

meets the preset conditions in the alarm registers (ALM_xxxx).

The ALM_CTRL register provides trigger source selection and

configuration controls, while the ALM_MAGx registers provide

threshold level controls.

Table 16. ALM_CTRL Bit Descriptions

Bit

Description (Default = 0x0000)

[15:6]

Not used

[5]

System alarm comparison polarity

1 = trigger when less than ALM_MAGS[11:0]

0 = trigger when greater than ALM_MAGS[11:0]

[4]

System alarm trigger source

1 = temperature, 0 = power supply

[3]

System alarm enable (ALM_MAGS)

1 = enabled, 0 = disabled

[2]

AIN2 alarm enable (ALM_MAG2)

1 = enabled, 0 = disabled

[1]

AIN1 alarm enable (ALM_MAG1)

1 = enabled, 0 = disabled

[0]

Acceleration alarm enable (ALM_MAGA)

1 = enabled, 0 = disabled

Table 17. ALM_MAGA Bit Descriptions

Bit

Description (Default = 0x0000)

[15:0]

Data bits for acceleration threshold setting;

twos complement, 19.073 mg/LSB.

Range = +8191/−8192 LSBs

Table 18. ALM_MAG1 and ALM_MAG2 Bit Descriptions

Bit

Description (Default = 0x0000)

[15:0]

Data bits for AIN1, AIN2 signal threshold setting;

twos complement, 305.18 μV/LSB.

Range = +8191/−8192 LSBs

Table 19. ALM_MAGS Bit Descriptions

Bit

Description (Default = 0x0000)

[15:12]

Not used.

[11:0]

Data bits for temperature or supply threshold setting.

Binary format matches CAPT_TEMP or CAPT_SUPPLY

format, depending on the ALM_CTRL[4] setting.

Configuring the device in the event capture mode requires four

steps: select which data channels to enable (ALM_CTRL), set

each threshold (ALM_MAGx), select event capture mode

(CAPT_CTRL) and start the capture mode operation (set

GLOB_CMD[11]). Each ALM_MAGx register has a

corresponding error flag in the DIAG_STAT register for

software monitoring of alarm conditions. Note that the system

alarm has an error flag in DIAG_STAT[11] but cannot trigger a

data capture.

Table 20. Example Event Mode Configuration Sequence

DIN

Description

0xA00C,

0xA102

Set acceleration trigger point at >+10 g and <−10 g by

setting ALM_MAGA = 0x020C.

0xA634,

0xA700

Set temperature error flag level at +60°C by setting

ALM_MAGS = 0x00C4.

0xA839

Set the system alarm as a greater-than-temperature

configuration and enable both acceleration and system

alarms by setting ALM_CTRL[7:0] = 0x39.

0xB61F

Keep DIO1 as a busy indicator and set DIO2 as a positive

alarm indicator by setting DIO_CTRL[7:0] = 0x1F.

0x9C5A

Set capture into event mode, enable automatic capture

store to flash, enable power-down between captures,

and set pre-event capture length to 128 samples by

setting CAPT_CTRL[7:0] = 0x5A.

0xBF08

Start the event capture mode by setting GLOB_CMD[11] = 1

GLOBAL COMMANDS

The GLOB_CMD register provides an array of single-write

commands for convenience. Setting the assigned bit in Table 21

to 1 activates each function. When the function completes, the

bit restores itself to 0. For example, clear the capture buffers using

a single DIN write sequence, DIN = 0xBF01. All of the commands

in the GLOB_CMD register require the power supply to be

within normal limits for the execution times listed in Table 21.

The execution times reflect the factory default configuration

where applicable and describe the time required to return to

normal operation.