Datasheet ADIS16137 (Analog Devices) - 10

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Data Sheet ADIS16137 OUTPUT DATA REGISTERS Table 12. TEMP_OUT Bit Descriptions Bits Description Table 8. Output Data Register Formats
[15:0] Temperature data; twos complement, 0.010697°C per
Register Address Measurement
LSB, 0°C = 0x0000 TEMP_OUT 0x02 Internal temperature GYRO_OUT2 0x04 Gyroscope, lower 16 bits
Table 13. Temperature, Twos Complement Format
GYRO_OUT 0x06 Gyroscope, upper 16 bits
Temperature Decimal Hex Binary
+85°C +7946 0x1F0A 0001 1111 0000 1010
Rotation Rate (Gyroscope)
+0.021394°C +2 0x0002 0000 0000 0000 0010 GYRO_OUT is the primary register for gyroscope output data +0.010697°C +1 0x0001 0000 0000 0000 0001 and uses 16-bit twos complement format for its data. Table 9 0°C 0 0x0000 0000 0000 0000 0000 provides the numerical format, and Table 10 provides several −0.010697°C −1 0xFFFF 1111 1111 1111 1111 examples for converting digital data into °/sec. −0.021394°C −2 0xFFFE 1111 1111 1111 1110 −40°C −3739 0xF165 1111 0001 0110 0101
Table 9. GYRO_OUT Bit Descriptions Bits Description DEVICE CONFIGURATION
[15:0] Gyroscope data; twos complement, 256°/sec per The control registers in Table 14 list a variety of user configuration 6300 LSB, 0°/sec = 0x0000 options. The SPI provides access to these registers, one byte at a
Table 10. GYRO_OUT, Twos Complement Format
time, using the bit assignments shown in Figure 13. Each register
Rotation Rate
has 16 bits, wherein Bits[7:0] represent the lower address, and
(°/sec) Decimal Hex Binary
Bits[15:8] represent the upper address. +1000 +24,609 0x6021 0110 0000 0010 0001 Figure 15 provides an example of writing 0x03 to Address 0x22 +512 ÷ 6300 +2 0x0002 0000 0000 0000 0010 (DEC_RATE[7:0]), using DIN = 0xA203. This example reduces +256 ÷ 6300 +1 0x0001 0000 0000 0000 0001 the sample rate by a factor of 8 (see Table 18). 0 0 0x0000 0000 0000 0000 0000
CS
−256 ÷ 6300 −1 0xFFFF 1111 1111 1111 1111 −512 ÷ 6300 −2 0xFFFE 1111 1111 1111 1110
SCLK
−1000 −24,609 0x9FDF 1001 1111 1101 1111
DIN
015 The GYRO_OUT2 register (see Table 11) captures the bit growth
DIN = 1010 0010 0000 0011 = 0xA203, WRITES 0x03 TO ADDRESS 0x22
1854- 1 associated with the decimation and FIR filters (see Figure 18) Figure 15. SPI Sequence for Setting the Decimate Rate to 8 (DIN = 0xA203) using an MSB justified format. The bit growth starts with the
Dual Memory Structure
MSB (GYRO_OUT2[15]), is equal to the decimation rate setting in Writing configuration data to a control register updates its SRAM DEC_RATE[4:0] (see Table 18), and grows in the LSB direction contents, which are volatile. After optimizing each relevant as the decimation rate increases. See Figure 14 for more details. control register setting in a system, set GLOB_CMD[3] = 1
Table 11. GYRO_OUT2 Bit Descriptions
(DIN = 0xA808) to backup these settings in the nonvolatile
Bits Description
flash memory. The flash backup process requires a valid power supply level for the entire processing time (see Table 1). Table 14 [15:0] Rotation rate data; resolution enhancement bits provides a user accessible, register memory map that includes a
D D = DEC_RATE[4:0]
column to identify the registers that are nonvolatile, through
GYROSCOPE DATA NOT USED
the flash memory backup. A yes in this column indicates that a register has a mirror location in flash and, when backed up
15 GYRO_OUT 0 15 GYRO_OUT2 0
properly, automatically restores itself during startup or after a
256 °/sec
014
BIT WEIGHT = LSB = GYRO_OUT2[16-D]
reset. Figure 16 provides a diagram of the dual memory structure
6300 × 2D LSB
1854- 1 that manages operation and stores critical user settings. Figure 14. Gyroscope Output Format, DEC_RATE[4:0] > 0
Internal Temperature MANUAL FLASH BACKUP
The TEMP_OUT register (see Table 12) provides an internal temperature measurement for observing relative temperature
NONVOLATILE VOLATILE FLASH MEMORY SRAM
changes in the environment. Table 13 provides several coding
(NO SPI ACCESS) (SPI ACCESS)
examples for converting the 16-bit twos complement number
START-UP
into units for temperature (°C).
RESET
016 1854- 1 Figure 16. SRAM and Flash Memory Diagram Rev. A | Page 9 of 20 Document Outline Features Applications General Description Functional Block Diagram Table of Contents Revision History Specifications Timing Specifications Timing Diagrams Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Theory of Operation Reading Sensor Data Output Data Registers Rotation Rate (Gyroscope) Internal Temperature Device Configuration Dual Memory Structure User Registers Digital Processing Configuration Internal Sample Rate Input Clock Configuration Digital Filtering Averaging/Decimation Filter Calibration Automatic Bias Correction (Autonull) Manual Bias Correction Restoring Factory Calibration Alarms Static Alarm Use Dynamic Alarm Use Alarm Reporting Alarm Example System Controls Global Commands Software Reset Memory Management Checksum Test General-Purpose Input/Output Data Ready Input/Output Indicator Example Input/Output Configuration Automatic Self Test Power Management Status Product Identification Applications Information Power Supply Considerations Prototype Interface Board Installation Tips Packaging and Ordering Information Outline Dimensions Ordering Guide