PNI RM3000 Evaluation Board - Manual (Page 15)

RM3000 Evaluation Board User Manual – June 2011 Page 15 of 19
Send 64
H
(value for the LSB for the Z axis - pointer automatically increments)
Set SSN to HIGH
5.2 Single-Axis Measurement (SAM) Operation
The SAM Command Byte initiates a sensor measurement on a single sensor, and sets up the
RM3000 Evaluation Board to output the measured values on the MISO line. Generally SAM
operation is not as efficient as MAM operation, except when only one sensor (in total) is to
be measured.
5.2.1 SAM SPI Activity Sequence
The SPI activity sequence for SAM operation is given below. SPI timing is discussed in
Section 4.3. The Return Byte is 9A
H
. Three (3) data bytes will be clocked out for a
single-axis measurement. The Command Byte is discussed below.
Figure 5-1: SPI Activity Sequence Diagram for SAM Operation
5.2.2 SAM Command Byte
The SAM Command Byte is defined as follows:
Bit # 7 6 5 4 3 2 1 0
Value 0 0 0 0 0 0 AS1 AS0