Acceleration Data Coding - Analog Devices ADXL180 iMEMS Manual

ACCELERATION DATA CODING

01 1111 1111
01 1111 1110
01 1111 1101
01 1111 1100
00 0000 0001
00 0000 0000
11 1111 1111
11 1111 1110
10 0000 0010
10 0000 0001
10 0000 0000
–FS
Figure 19. 10-Bit ADC Transfer Characteristic
Table 12. DAT Data Bit Options
DAT Definition
0 10-bit data sensor data transmitted. 8-bit Phase 2
configuration data left justified in 10-bit data frame
(default).
1 8-bit sensor data transmitted.
The sensor data coding is dependent on the configuration
register bit settings. Either 8-bit or 10-bit sensor data can be
transmitted. This 8-bit or 10-bit data range is either full range
or reduced range. Whether the data range is full or reduced
depends on the setting of the state vector disable and auto-zero
enable configuration register bits. For more information, see
Table 13.
Table 13. Full and Reduced Sensor and Device Data Ranges
1 2
SVD AZE
0 0
0 1
1 0
1 1
1
SVD is the state vector disable configuration bit.
2 AZE is the auto-zero enable configuration bit.
3
A configuration error is reported if Phase 2 Mode 0 is selected with the state
vector disabled (SVD = 1). The ADXL180 transmits a configuration error code
during run time and no sensor data is transmitted.
0
+FS
ACCELERATION INPUT
Data Range
Full
Reduced
Reduced 3
3
Reduced
Table 14. 8-Bit Full Sensor Data Range Coding
Decimal Hex
+127 0x7F
+126 0x7E
+125 0x7D
... ...
+1 0x01
0 0x00
−1 0xFF
... ...
−126 0x82
−127 0x81
−128 0x80
Table 15. 10-Bit Full Sensor Data Range Coding
Decimal Hex
+511 0x1FF
+510 0x1FE
+509 0x1FD
... ...
+1 0x01
0 0x00
−1 0x3FF
... ...
−510 0x202
−511 0x201
−512 0x200
Table 16. 8-Bit Reduced Sensor Data Range Coding
Decimal Hex
+116 0x74
... ...
0 0x00
... ...
−116 0x8C
Table 17. 10-Bit Reduced Sensor Data Range Coding
Decimal Hex
+464 0x1D0
... ...
0 0x000
... ...
−464 0x230
Rev. 0 | Page 23 of 56
Binary (Twos
Complement) Description
0111 1111 Most positive (+FS)
acceleration value
0111 1110 ...
0111 1101 ...
... ...
0000 0001 ...
0000 0000 Zero (0) acceleration value
1111 1111 ...
... ...
1000 0010 ...
1000 0001 ...
1000 0000 Most negative (−FS)
acceleration value
Binary (Twos
Complement) Description
01 1111 1111 Most positive (+FS)
acceleration value
01 1111 1110 ...
01 1111 1101 ...
... ...
00 0000 0001 ...
00 0000 0000 Zero (0) acceleration value
11 1111 1111 ...
... ...
10 0000 0010 ...
10 0000 0001 ...
10 0000 0000 Most negative (−FS)
acceleration value
Binary (Twos
Complement) Description
0111 0100 Most positive (+FS)
acceleration value
... ...
0000 0000 Zero (0) acceleration
value
... ...
1000 1100 Most negative (−FS)
acceleration value
Binary (Twos
Complement) Description
01 1101 0000 Most positive (+FS)
acceleration value
... ...
00 0000 0000 Zero (0) acceleration value
... ...
10 0011 0000 Most negative (−FS)
acceleration value
ADXL180