Datasheet ADIS16135 (Analog Devices) - 9

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ADIS16135 Data Sheet BASIC OPERATION
The ADIS16135 is an autonomous system that requires no user
Table 7. Generic Master Processor SPI Settings
initialization. Once it has a valid power supply, it initializes itself
Processor Setting Description
and starts sampling, processing, and loading sensor data into Master The ADIS16135 operates as a slave. the output registers. DIO1 pulses high after each sample cycle SCLK Rate ≤ 2 MHz Maximum serial clock rate. concludes. The SPI interface enables simple integration with SPI Mode 3 CPOL = 1 (polarity), CPHA = 1 (phase). many embedded processor platforms, as shown in Figure 10 MSB-First Mode Bit sequence. (electrical connection) and Table 6 (processor pin descriptions). 16-Bit Mode Shift register/data length.
I/O LINES ARE COMPATIBLE WITH 5V VDD 3.3V OR 5V LOGIC LEVELS READING SENSOR DATA 10 11 12
A single register read requires two 16-bit SPI cycles. The first
SYSTEM PROCESSOR SS 6 CS ADIS16135
cycle requests the contents of a register using the bit assignments
SPI MASTER SCLK 3 SCLK
in Figure 13. Then the register contents follow on DOUT
MOSI 5 DIN
during the second sequence. Figure 11 includes three single
MISO 4 DOUT
register reads in succession. In this example, the process starts
IRQ 7 DIO1
with DIN = 0x0600 to request the contents of the GYRO_OUT
13 14 15
register and follows with 0x0400 to request the contents of the 10 0 8- GYRO_OUT2 register and with 0x0200 to request the contents 88 08 of the TEMP_OUT register. Full duplex operation enables Figure 10. Electrical Connection Diagram processors to use the same 16-bit SPI cycle to read data from
Table 6. Generic Master Processor Pin Names and Functions
DOUT while requesting the next set of data on DIN. Figure 12
Pin Name Function
provides an example of the four SPI signals when reading SS Slave select GYRO_OUT in a repeating pattern. Note that DOUT starts to IRQ Interrupt request represent GYRO_OUT during the second 16-bit SPI cycle. MOSI Master output, slave input
DIN 0x0600 0x0400 0x0200
MISO Master input, slave output 011 8- SCLK Serial clock
DOUT GYRO_OUT GYRO_OUT2 TEMP_OUT
888 0 Figure 11. SPI Read Example The ADIS16135 SPI interface supports full duplex serial com- munication (simultaneous transmit and receive) and uses the
CS
sequences shown in Figure 13 for DIN/DOUT bit coding. Table 7
SCLK
provides a list of the most common settings that require attention
DIN DIN = 0000 0110 0000 0000 = 0x0600
to initialize a processor serial port for the ADIS16135 SPI interface.
DOUT
2 01 88-
DOUT = 1111 1001 1101 1010 = 0xF9DA = –1574 LSBs ≥ –19.675°/sec
88 0 Figure 12. SPI Read Example, Second 16-Bit Sequence
CS SCLK DIN R/W A6 A5 A4 A3 A2 A1 A0 DC7 DC6 DC5 DC4 DC3 DC2 DC1 DC0 R/W A6 A5 DOUT D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D15 D14 D13 NOTES 1. DOUT BITS ARE PRODUCED ONLY WHEN THE PREVIOUS 16-BIT DIN SEQUENCE STARTS WITH R/W = 0.
3 -01
2. WHEN CS IS HIGH, DOUT IS IN A THREE-STATE, HIGH-IMPEDANCE MODE, WHICH ALLOWS MULTIFUNCTIONAL USE OF THE LINE
888
FOR OTHER DEVICES.
08 Figure 13. SPI Communication Bit Sequence Rev. F | Page 8 of 20 Document Outline Features Applications General Description Functional Block Diagram Revision History Specifications Timing Specifications Timing Diagrams Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Basic Operation Reading Sensor Data Output Data Registers Rotation Rate (Gyroscope) Internal Temperature Dual Memory Structure User Registers Digital Processing Configuration Internal Sample Rate Input Clock Configuration Digital Filtering Averaging/Decimation Filter Calibration Automatic Bias Correction Manual Bias Correction Alarms Static Alarm Use Dynamic Alarm Use Alarm Reporting Alarm Example System Controls Global Commands Software Reset Memory Management Checksum Test General-Purpose I/O Data Ready I/O Indicator Example I/O Configuration Self-Test Power Management Status Product Identification Applications Information Breakout Board Installation Tips Outline Dimensions Ordering Guide