ADV7184 I2C Programming Example

Hi Owen,

Are you using a DSP from ADI? If not, does the processor have in built I2C hardware port?

Regards

Prasanth.

Hello Prasanth,

I'm using the BF533 STAMP board & uClinux that implemenets a 'bit-bashing' method of I2C.

Regards,

Owen

Owen,

As you might be aware, GPIO based bit banging driver is already available with Linux. They also have video for linux, that includes the ADV7183 driver.

http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:drivers:v4l_blackfin_cameradocs.blackfin.uclinux.org/doku.php

If you need any more details on the above, you have to reach the appropriate forum (Blackfin uClinux and related software is dealt only there):

http://blackfin.uclinux.org/gf/

For non-linux code (for ADV7183, tested on VDSP), you can check out the ASM based I2C codes here:

https://www.analog.com/en/embedded-processing-dsp/blackfin/processors/code-examples/Blackfin_Code_Examples/resources/fca.html

ADV7183 and ADV7184 are closely related. So you just need to look at the appropriate register programming, if you have a code for I2C emulation.

If you have any direct questions on the Linear parts, you can also mail our Linear Team: linear.apps@analog.com

Regards

Prasanth.

Prasanth,

Thanks for the reply. I've been looking at the ADV7183B I2C programming examples (table 87 of the datasheet) but have hit something that seems strange. Below is shown some of the code taken from datasheet which I have annotated.

Table 87. Mode 1 CVBS Input
Register Address Register Value Notes

0x00 0x04 CVBS input on AIN5.
0x15 0x00 Slow down digital clamps.
0x17 0x41 Set CSFM to SH1.
0x1D 0x40 Enable 28 MHz crystal.
0x0F 0x40 TRAQ.
0x3A 0x16 Power down ADC 1 and ADC 2.
0x3D 0xC3 MWE enable manual window.
0x3F 0xE4 BGB to 36.
0x50 0x04 Set DNR threshold to 4 for flat response.

0x0E 0x80 ADI recommended programming sequence. This sequence must be followed exactly when setting up the decoder.
0x50 0x20 Recommended setting.
0x52 0x18 Recommended setting.
0x58 0xED Recommended setting.
0x77 0xC5 Recommended setting.
0x7C 0x93 Recommended setting.
0x7D 0x00 Recommended setting.
0x90 0xC9 Recommended setting. Read only
0x91 0x40 Recommended setting.
0x92 0x3C Recommended setting.
0x93 0xCA Recommended setting.
0x94 0xdD Recommended setting.
0xCF 0x50 Recommended setting. Not listed in datasheet
0xD0 0x4E Recommended setting.
0xD6 0xDD Recommended setting.
0xE5 0x51 Recommended setting.
0xD5 0xA0 Recommended setting.
0xD7 0xEA Recommended setting.
0xE4 0x3E Recommended setting.
0xE9 0x3E Recommended setting.
0xEA 0x0F Recommended setting.
0x0E 0x00 Recommended setting.

As you can see in the datasheet it attempts to write values to 0x90 -> 0x94 which are listed in the datasheet as read only.

Also it writes values to registers which as far as I can see are not mentioned in the ADV7183B datasheet. As I don't know what these registers are it's impossible to find the corresponding register on the ADV7184.

Can you provide some assistance/ reason for the above sequence?

Many thanks,

Owen

Hi Owen,

You might want to post the question to our Linear IC support team: linear.apps@analog.com, since they are in a better position to comment on questions related to the Mixed-signal parts (this Forum is currently limited to the Processors from ADI).

If you are trying to modify the existing code, you could begin with writing in to few registers of ADV7184, and read them back subsequently (if you are currently unsure about what registers to program, for the application). By doing so, you can verify the i2c programming-software and the hardware setup. To capture a video frame, you might still have to program some more registers.

Regards

Prasanth.

For others that may find it useful I attach the reply I got from Linear support.

This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

Thank you,
EZ Admin