Datasheet ADIS16445 (Analog Devices) - 17

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ADIS16445 Data Sheet INPUT/OUTPUT CONFIGURATION DATA READY INDICATOR Table 27. GPIO_CTRL (Base Address = 0x32), Read/Write
The data ready indicator provides a signal that indicates
Bits Description (Default = 0x0000)
when the registers are updating, so that system processors can [15:12] Not used avoid data collision, a condition when internal register updates 11 General-Purpose I/O Line 4 (DIO4) data level happen at the same time that an external processor requests it. 10 General-Purpose I/O Line 3 (DIO3) data level The data ready signal has valid and invalid states. Using the 9 General-Purpose I/O Line 2 (DIO2) data level transition from invalid to valid to trigger an interrupt service 8 General-Purpose I/O Line 1 (DIO1) data level routine provides the most time for data acquisition (before [7:4] Not used the next register update). See Figure 4 and Table 2 for specific 3 General-Purpose I/O Line 4 (DIO4) direction control timing information. 1 = output, 0 = input MSC_CTRL[2:0] (see Table 24) provide control bits for ena- 2 General-Purpose I/O Line 3 (DIO3) direction control bling this function, selecting the polarity of the valid state and 1 = output, 0 = input I/O line assignment (DIO1, DIO2). The factory default setting 1 General-Purpose I/O Line 2 (DIO2) direction control of MSC_CTRL[2:0] = 110 establishes DIO1 as a data ready out- 1 = output, 0 = input put line and assigns the valid state with a logic high (1). Set 0 General-Purpose I/O Line 1 (DIO1) direction control MSC_CTRL[2:0] = 100 (DIN = 0xB404) to change the polarity of 1 = output, 0 = input the data ready signal on DIO1 for interrupt inputs that require negative logic inputs for activation.
Example Input/Output Configuration GENERAL-PURPOSE INPUT/OUTPUT
For example, set GPIO_CTRL[3:0] = 0100 (DIN = 0xB204) to set DIO3 as an output signal pin and DIO1, DIO2, and DIO1, DIO2, DIO3, and DIO4 are configurable, general-purpose DIO4 as input signal pins. Set the output on DIO3 to 1 by set- input/output lines that serve multiple purposes. The data ting GPIO_CTRL[10] = 1 (DIN = 0xB304). Then, read ready controls in MSC_CTRL[2:0] have the highest priority GPIO_CTRL[7:0] (DIN = 0x3200) and mask off GPIO_CTRL[9:8] for configuring DIO1 and DIO2. The alarm indicator controls in and GPIO_CTRL[11] to monitor the digital signal levels on ALM_CTRL[2:0] have the second highest priority for configuring DIO4, DIO2, and DIO1. DIO1 and DIO2. The external clock control associated with SMPL_PRD[0] has the highest priority for DIO4 configuration (see Table 28). GPIO_CTRL in Table 27 has the lowest priority for configuring DIO1, DIO2, and DIO4, and has absolute con- trol over DIO3. Rev. F | Page 16 of 22 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 User Registers User Interface Reading Sensor Data Burst Read Function SPI Read Test Sequence Device Configuration Dual Memory Structure Output Data Registers Gyroscopes Accelerometers Internal Temperature System Functions Global Commands Product Identification Self-Test Function Status/Error Flags Memory Management Checksum Test Input/Output Configuration Data Ready Indicator General-Purpose Input/Output Example Input/Output Configuration Digital Processing Configuration Gyroscopes/Accelerometers Input Clock Configuration Digital Filtering Dynamic Range Calibration Gyroscopes Gyroscope Bias Error Estimation Gyroscope Bias Correction Factors Single Command Bias Correction Accelerometers Accelerometer Bias Error Estimation Accelerometer Bias Correction Factors Point of Percussion Alignment Flash Updates Restoring Factory Calibration Alarms Static Alarm Use Dynamic Alarm Use Alarm Reporting Alarm Example Applications Information Mounting Tips Power Supply Considerations ADIS16445/PCBZ Installation PC-Based Evaluation Tools Outline Dimensions Ordering Guide