PNI RM3000-F Sensor Suite - Manual (Page 37)

PNI Sensor Corporation Doc #1016102 r04
RM3000-f & RM2000-f Sensor Suite User Manual Page 37
6.1.1 Legacy Operation SPI Activity Sequence
The SPI activity sequence is given below for Legacy operation. SPI timing is discussed
in Section 4.4. The Return Byte is 0x9B. If the Return Byte is 0x9A, then the 3D MagIC
is in Standard Mode. Two (2) data bytes will be clocked out for a Legacy measurement.
The Command Byte is discussed below.
Figure 6-1: SPI Activity Sequence Diagram for Legacy Operation
6.1.2 Legacy Command Byte
The command byte to initiate a sensor measurement is defined as follows:
Bit # 7 6 5 4 3 2 1 0
Value 0 PS2 PS1 PS0 0 0 AS1 AS0
PS0-PS2: Period Select
Selects the number of sensor circuit oscillation cycles (cycle counts) to be counted
while simultaneously using the internal fixed reference clock to measure the time to
obtain this count.