MMA6222EG
Sensors
20 Freescale Semiconductor
The first data transmitted by MMA62XXEG following reset is the Request Error message shown below. This occurs because
MMA62XXEG transmits during Phase Two and there is no corresponding Phase One for the first transfer.
Figure 4-3 Request Error Frame
4.1.2 Command Format
The following abbreviations are used in the following figures.
Commands are transferred from the SPI master to MMA62XXEG. Commands fall into three categories: acceleration data re-
quests, register operations and device test. Acceleration data requests are initiated when bit 13 from the master is set to a
logic ‘1’ state. Register operations and device test are when bit 13 is set to logic’0’ and are further distinguished by the states of
bits 15 and 14.
4.1.3 Acceleration Data Transfers
Acceleration data requests are initiated when bit 15 from the master is set to a logic ‘0’ state and bit 13 is set to a logic ‘1’ state.
The axis associated with the acceleration to be transferred is determined by D
IN
bit 14.
Figure 4-4 Acceleration Command Format
Bit Name Description
Bit Address
D
IN
D
OUT
A[4:0] Register address 12:8 12:8
D[9:0] 10-bit acceleration data N/A 9:0
Acc Acceleration data indicator 13 13
AXIS Axis specifier 14 14
P Parity N/A 12
S[1:0] Status N/A 11:10
0
SCLK
BIT
D
OUT
CS
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
00P0111000 00RE00
SCLK
BIT
D
IN
CS
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
AXIS
0
AccXXXXXXXXXXXXX
