PNI RM3000-F Sensor Suite - Manual (Page 27)

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RM3000-f & RM2000-f Sensor Suite User Manual Page 27
R
EXT
(External Timing Resistor)
R
EXT
ties to the external timing resistor for the high-speed clock. The recommended
value for the resistor and associated clock speed are defined in Table 3-1.
Sensor Drive and Measurement Pins
The various sensor drive and measurement pins should be connected to the sensors.
For a north-east-down (NED) reference frame, the connections should be as defined
in Figure 4-3.
4.4 SPI Timing Requirements
When implementing a SPI port, whether a dedicated hardware peripheral port or a software-
implemented port using general purpose I/O (also known as Bit-Banging), the timing
parameters, defined in Figure 4-4 and specified in Table 4-2, must be met to ensure reliable
communication. Note that Standard Mode and Legacy Mode timing requirements are
identical with the exception of Legacy Mode utilizing the CLEAR line. The SPI clock
(SCLK) should run at 1 MHz or less. Generally data is considered valid while SCLK is
HIGH, and data is in transition when SCLK is LOW. The clock polarity used with the 3D
MagIC is zero (exclusively CPOL=0). Data is present on MISO or should be presented on
MOSI before the first low to high clock transition (exclusively CPHA = 0).
Figure 4-4: SPI Timing Diagram