ADIS16204

Rev. 0 | Page 13 of 24

DATA OUTPUT REGISTER ACCESS

Table 6 provides an overview of each data output register,

along with their function, address, and relevant decoding

information.

Sensor Output Data

The ADIS16204 provides access to X- and Y-axis acceleration

measurements, combined accelerations measurements (root

sum square of X and Y), peak acceleration, power supply meas-

urements, temperature measurements, an auxiliary 12-bit

ADC channel, and the event-capture buffer memory.

Peak Sample and Hold Output Registers

The ADIS16204 monitors the X, Y and XY acceleration

measurements and holds the maximum value and polarity

for each parameter. The X_PEAK_OUT, Y_PEAK_OUT, and

XY_PEAK_OUT registers provide access to these maximum

values. See the COMMAND register for clearing these registers.

Register Access

This output data is continuously updating internally, regardless

of user read rates. The bit map in Table 5 describes the structure of

all output data registers in the ADIS16204. The upper byte is

always first in register read sequences.

Table 5. Output Bit Assignments

MSB

LSB

ND

EA

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

The MSB holds the new data (ND) indicator. When the output

registers are updated with new data, the ND bit goes to a 1 state.

After the output data is read, it returns to a 0 state. The EA bit

is used to indicate a system error or an alarm condition that

can result from a number of conditions, such as a power supply

that is out of the specified operating range (see the Status and

Diagnostics section for more details). The output data is either

12 bits or 14 bits in length. For all of the 12-bit output data,

Bit D13 and Bit D12 are assigned don’t care status.

The output data register map is located in Table 6 and provides

all of the necessary details for accessing each register’s data.

Figure 23 provides an example of the SPI sequence.

Table 6. Data Output Register Information

Name

Function

Register

Resolution (Bits)

Data Format

Scale Factor

(per LSB)

SUPPLY_OUT

Power supply

0x03, 0x02

12

Binary

1.22 mV

XACCL_OUT

X-axis acceleration

0x05, 0x04

14

Twos complement

17.125 mg

YACCL_OUT

Y-axis acceleration

0x07, 0x06

14

Twos complement

8.407 mg

AUX_ADC

Auxiliary analog input data

0x09, 0x08

12

Binary

0.61 mV

TEMP_OUT1

Sensor temperature data

0x0B, 0x0A

12

Binary

−0.47°C

X_PEAK_OUT2

Peak, X-axis acceleration

0x0D, 0x0C

14

Twos complement

17.125 mg

Y_PEAK_OUT2

Peak, Y-axis acceleration

0x0F, 0x0E

14

Twos complement

8.407 mg

XY_RSS_OUT3

X-Y combined acceleration (RSS)

0x19, 0x18

14

Binary

17.125 mg

XY_PEAK_OUT2,3

Peak, X-Y combined output (RSS)

0x1B, 0x1A

14

Binary

17.125 mg

CAPT_BUF_14

Capture Buffer 1 Output Register

0x1D, 0x1C

Capture Buffer 2 Output Register

0x1F, 0x1E

See the Alarm Detection and Event Capture section, Table 37,

and Table 38

COMMAND register.

CS

SCLK

DIN

DOUT

ADDRESS = 000101

W/R BIT = 0

DATA = 1011 1101 1101 1110

NEW DATA, NO ALARM, XACCL_OUT = –10.377g

Figure 23. Example of an Output Timing/Coding Diagram