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The I2C of ADV7282-M  can't read the value

Question asked by Luo on May 21, 2015
Latest reply on Jun 5, 2015 by Rob.Analog

Dear All Friends ,

We used the ADV7282-M to do a vehicle monitoring product . Receive four  CVBS signals  from camera . The platform is the

MTK6582 .

 

1.jpg

 

As this picture ,It is a single register  operation  : 0x0f, 0x00, 0x40.   You can see that the i2c  command is right ,  and this step can go to exit  PWR down mode .

 

adi_read_0x0f_no_ack.jpg

 

As this picture ,   the write value to  0x0f register :0x40, 0x0f, 0x41。But we can see from the oscilloscope ,  the ninth bit ACK did not pull low . so that we can't see the wave of 0x00,the i2c get Read failed. I have a puzzle , 0x40, 0x0f have a continuing high level ,an then host send the 0x41order 。I don't know whether it's normal ?

 

i2c  operations :

 

 

root@ratech82_cwet_rgk_kk:/ # i2cset -f -y 1 0x20 0x0f 0x00

root@ratech82_cwet_rgk_kk:/ #

root@ratech82_cwet_rgk_kk:/ # i2cget -f -y 1 0x20 0x0f

Error: Read failed

root@ratech82_cwet_rgk_kk:/ # i2cdump -f -y 1 0x20

No size specified (using byte-data access)

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef

00: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

10: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

20: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

30: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

40: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

50: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

60: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

70: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

80: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

90: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

a0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

b0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

c0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

d0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

e0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

f0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX    XXXXXXXXXXXXXXXX

root@ratech82_cwet_rgk_kk:/ #

 

So could you kindly give me some suggestion , whether you have handled such problems in ADV7282-M ? many thanks !

QQ图片20150521165338.png

 

Outcomes