Ud[7:0] User Data Bits; Ud8 Configuration Bit; Bde; Scoe - Analog Devices ADXL180 iMEMS Manual

UD[7:0] USER DATA BITS

The user register is for arbitrary user data. It does not have any
influence on sensor operation. This data is transmitted during
Phase 2 of the state machine. For more information on trans-
mission format and timing, in particular depending on the
setting of MD bits, see the ADXL180 State Machine section.
Table 45. User Data Bit Definitions
Bit
Names Definition
UD0 User Data Bit 0. No function, data only.
UD1 User Data Bit 1. No function, data only.
UD2 User Data Bit 2. No function, data only.
UD3 User Data Bit 3. No function, data only.
UD4 User Data Bit 4. No function, data only.
UD5 User Data Bit 5. No function, data only.
UD6 User Data Bit 6. No function, data only.
UD7 User Data Bit 7. No function, data only.

UD8 CONFIGURATION BIT

Table 46. UD8 Configuration Bit
UD8 Definition
0 Reserved, don't care (default)
1 Reserved, don't care
The value of the RS bit may be transmitted during Phase 2, inde-
pendent of UD[7:0], depending on the selection of the MD bits.

BDE

Table 47. Bus Discharge Enable
BDE Definition
0 Bus discharge disabled (default).
1 Bus discharge enabled. Only active when SYEN = 1.
The bus discharge enable (BDE) bit enables a discharge of the
bus voltage after a synchronization pulse is detected. If the BDE
bit is set, the ADXL180 changes the bus current (I
I to I when a valid synchronization pulse has been detected.
IDLE SIG
See the Synchronous Communication section for more details
and timing information.

SCOE

Table 48. SCOE V Signal Chain Output Enable
SCO
SCOE Definition
0 V output disabled. (Default.)
SCO
1 V output enabled. Analog output prior to ADC
SCO
conversion is present on V
impedance input or data or sensor data may be
adversely affected.
) level from
BUS
pin. Connect V to high
SCO SCO
Rev. 0 | Page 51 of 56

FDLY

Table 49. Fixed Delay Mode
FDLY Definition
0 Fixed delay mode disabled (default).
1 Fixed delay mode enabled. Device transmits data in the
time slot delayed by t

ADME

Table 50. Autodelay Mode Enable (ADME ) Options
ADME Definition
0 Autodelay mode disabled. The part does not check for
a second device on the line and does not pull any extra
current during startup. (Default.)
1 Autodelay mode detection enabled. I
6 ms at power-up.

STI

Table 51. Self Test Internal (STI) Options
STI Definition
0 External self-test. User must monitor self-test data to
verify proper operation. Device does not monitor its own
response to the self-test stimulus. (Default.)
1 Internal self-test. The device monitors its own self-test
data to determine proper operation.
Table 52. Phase 3 Data Transmitted When STI = 1
MD1 MD0 Data
0 0 Device OK
0 1 Range
1 0 Delimiter
1 1 Device OK
FC[1:0]
Table 53. FC Low-Pass Filter Bandwidth Frequency Select Codes
FC1 FC0 −3 dB LP Frequency
0 0 400 Hz
0 1 200 Hz
1 0 100 Hz
1 1 800 Hz
RG[2:0]
Table 54. RG[2:0] Sensor Range Select Codes
RG2 RG1 RG0
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
ADXL180
as defined by DLY[2:0].
DLY
pull-down for
DET
Range
±50 g
±100 g
±250 g
±150 g
±200 g
±350 g
±500 g
Not used