IMX6DL SCCB group write

[ifzhao]

Dear all,

When I was trying to implement the AFC(auto focus control) , I'm really struck by the amount of registers to set, which reaches up to 4000. Then I set them one by one and it works. However the setting process will take about 2~3 seconds, that's not acceptable to the end users. Can anyone tell me how to implement the SCCB group write on IMX6DL platform?

Thanks!

[igorpadykov]

Hi If

OV datasheets in sect.SCCB interface describes group write as follows:

The SCCB will enter group write mode after writing to register 0x3212 with a
valid group ID. The subsequent registers will be held to the buffer specified by
the group_id instead of writing to the registers..Setting group_hold_end to 1
will exit the group write mode. After that, setting both group_launch and
group_launch_en to 1 will write the buffered values to the real registers.

One can check documentation for group write examples.

Best regards
igor
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[ifzhao]

Dear Igor,

It's very kind of you to give an advice. However, we both misunderstand the "group write". It means on the camera side, after it receive data through i2c port, it could decide to write to register immediately or do it soon later. The "group write" enable the camera MCU to buffer the data and just write them into registers in a frame boundary. This do not make much difference in time saving. Because, still, we need to transfer all the registers' values by i2c to camera, which is the mostly time-costly part in this process.

Finally, I decided to write the registers in the probing stage and it works.

Thanks!