MMA68XX initialization

shimasaadat — Tue, 03 Feb 2026 22:52:04 GMT

Hi,

I’m new at working with MMA68xx. I work on a reverse engineering project and read the micro commands and sensor responses through a SPI interface on the other test board. The initial state commands and responses are as below:

16 Clock cycles	commands	responses
1st	0X4A00	0X0E00
2nd	0X4AC0	0X3E00
3rd	0XCA40	0X3E00

Every command is sent in 16 -clock cycles and its response come from sensor in the next 16 clock cycles.

The first command is sent in the first 16 clock cycles according to the SPI interface the response message in this step must be 0X0000 but in first clock cycle I have a response which says Invalid register address….

Another question:

These 3 commands reset the device but to terminate the reset a read of DEVCTL register is needed (It is written in datasheet), but after these commands I can’t find this command…

Re: MMA68XX initialization

reyes — Mon, 06 Oct 2014 13:33:35 GMT

Hi shima saadat,

Here is another thread from the Freescale Communities which might give you some clues.

It talks about configuring the MMA68xx.

MMA68xx initialization

And as mentioned in the communities thread: Information (hardware and source code) is available at Automotive Sensors Tower System Module Freescale

Refer driver for MMA6800.

Have a great day,
Jose Reyes

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