TAS6584-Q1: TAS6584: Time to "decide" the i2c address

Hi 

  This should be a normal behavior.

   The address detection is several stage comparator and acting one by one. Some address only need one stage and could report the results directly, and some other address would tell DSP that need more stage results to check.

Hello

so how long should I wait to be sure that the address detection has happened for sure? Is 200us enough or is it better to wait longer? How much longer?

regards

Hi 

  Speaking of power on sequence, we suggest to wait 10ms after pull up PDN pins, and then start other operation. Not only the address deteciton you mentioned, there's also other LDO need time to be fully ready.

Shadow He said:

Speaking of power on sequence, we suggest to wait 10ms after pull up PDN pins

Here Yanming Gong says that 200us are enough. And he spoke with the design team to confirm this.

Who did you talk to? Who are these "we" you refer to?

So you deny Yanming Gong and the design team?

Regards

Max

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Hi Max

  I'm talking about the sequence, and it has descripting in the datasheet chapter 8.3.1.1. Please follow it.

  And it should be 4ms time for power up, and 10ms for power down.

I, on the other hand, was talking about the i2c transactions that occur after raising PD.

regards

Max

Hi Max

  I2C config is also part of the sequence, please wait 4ms after PND pull up, thanks.

Shadow He said:

please wait 4ms after PND pull up

But wait 4ms to do what? To raise STBY? Don't worry about that, we wait tens of ms (see here).

I was asking how long should I wait before starting i2c transactions. And you tell me to wait 4ms. Look at the time diagram on the datasheet.

I want to know how small A can be. So how long should I wait between PD raised and i2c start. And it is less then 4ms since it's clear on the schematic that i2c starts before 4ms.
Experimentally we measured A about 200us. And this was also confirmed by Yamming Gong here.

Is it clear now?

regards

Max

Hello Dylan,

Thank you for your response!

We have one last question: in our initialization we also configure some registers from book 8C page 02 (from 0x44 to 0x47), should we wait the 4ms before configuring them? Can we write them while the STBY pin is still low or so we have to raise it and wait for the LOAD DIAG to finish as we see in the image of the datasheet?

Marco