RDAIRPABPSI5UG , Rev. 2.0
Freescale Semiconductor
17
Describing the Device Functions
5.1.9.3
Diagnostics
The firmware can monitor the operation of the main ASSP through the STATUS and AI_CONTROL registers.
5.2 MMA6813KW - Local ECU Acceleration Sensor
The local ECU acceleration sensor is a dual channel device which also includes a safing block. At start up, the configuration, offset
cancellation, and self test of the device, occur before the configuration is complete ('ENDINIT' set) and the device goes into normal
operation.
5.2.1
Configuration - General
The general configuration sets up the data format, whether offset monitoring is enabled, and the functionality of the ARM_X and ARM_Y
output pins. When configuration is complete, the ENDINIT bit is set and this locks out access to the configuration registers.
5.2.2
Configuration - Axis Operation
The axis operation configuration triggers self-test and selects one of the low pass filter options for each axis.
5.2.3
Configuration - Arming Operation
The arming operation configuration defines the arming pulse stretch period and the arming window, which has different meanings,
depending on which arming mode is configured.
Table 16.
Diagnostics
Define
Function
Config Register
Diagnosis
Comment
MC33789
Diagnostics
–
STATUS, AI_CONTROL
Table 17. Configuration - General
Define
Function
Config Register
Diagnosis
Comment
MMA6813KW
Configuration
DEVCFG
–
Table 18. Configuration - Axis Operation
Define
Function
Config Register
Diagnosis
Comment
MMA6813KW
Configuration
DEVCFG_X,
DEVCFG_Y
–
Table 19. Configuration - Arming Operation
Define
Function
Config Register
Diagnosis
Comment
MMA6813KW
Configuration
ARMCFG_X,
ARMCFG_Y
–