AnsweredAssumed Answered

Problem Writing to ADV7612

Question asked by jasonuy on Apr 10, 2017
Latest reply on May 4, 2017 by GuenterL



I have an ARM based board connected to the EVAL ADV7612-7511P board.  I can write to ADV7612 using the Blackfin chip on the eval board but I'm unable to write to it using my ARM based board (where the SCL,SDA,GND pins are connected).


I have a logic analyzer connected to the I2C bus and I'm comparing the write cycle from my ARM chip and the Blackfin chip.  The only difference I can see is that the Blackfin pulses the data signal at the end so that there is a low to high transition between the ACK and STOP bit.  On my CPU, the SDA pin is low for two clock cycles are data is written.  I believe functionally both should be acceptable.  I've attached the capture from both CPU.  Can you tell me if you see anything out of the ordinary?  


These are the steps for my test.

1. ARM CPU writes a value to a register

2. BF CPU reads the value


Unfortunately I cannot test the other way (BF Writes and ARM CPU reads) yet since I'm having problems reading at the moment.


Failing Write using my ARM CPU

ARM CPU write


Successful Write using BF CPU on EVAL board

BF512 On board CPU write