RT1060 config boot mode pin to normal function pin.

[StephenYeh]

Hi Sir,

We will set BT_CFG[0] (GPIO_B0_04)and BT_CFG[1] (GPIO_B0_05) switched to I2C after bootup after 0.38ms. So there is a concern for the timing of the boot mode setting.
 
In my case => CFG0/1 is low at the moment of POR_B signal goes high. After 0.38 ms, BT_CFG[0] (GPIO_B0_04)and BT_CFG[1] (GPIO_B0_05) will be switched to 3.3V(external pull high) for the use of the I2C functoin pin.
In this case, is the configuration of BT_CFG[0] (GPIO_B0_04)and BT_CFG[1] (GPIO_B0_05) both low? Since timing is not mentioned,

I check the reference manual the boot mode will check POR_B rising edge, so our config. setting is OK, right.
Need your help to check is it right or not.

[StephenYeh]

Hi Kerry

You are using the I2C, do you add the external pull up resistor or not? => Yes, we do. But we add the pull up resistor after the SW, so it will stay 0 for about 0.38-0.48 ms.
 
So, you need to make sure, you should give the related time to the CFG0, CFG1 as low for booting => What is the related time?
The waveform we have is as follow

We want to know that we try to delay pull high signal (config 0/1) to avoid boot up setting.

We check the RM file, that Boot mode inpurt on the rising edge of the POR_B.

So is the 0.38ms ll enough for the boot mode sampling, right?

[StephenYeh]

Hi Kerry,

Thank support.

No issue about this.

Due to the pin shortage, we want to evaluate the config pin to function pin.

Would you share the delay timing for us, if 0.38ms not enough?

[kerryzhou · Accepted solution]

Hi @StephenYeh ,

   The time is very easy to testing, you can test it.

   To the BOOT_CFG0, CFG1, it should be 0 during booting.

   After boot, in the customer app code, you can configure it as GPIO and output high, then you can use oscillator to test the time, POR when BOOT_CFG0, CFG1 is low, to CFG0, CFG1 high, test that time duration, then you can know the detail time.

   So, you need to make sure, you should give the related time to the CFG0, CFG1 as low for booting, after code is entered, you can change it to the I2C and pull high.

Wish it helps you!

Best Regards

Kerry

[kerryzhou]

Hi @StephenYeh ,

   BT_CFG[0] (GPIO_B0_04)and BT_CFG[1] (GPIO_B0_05) should be externaly connect to 0 during the boot. You are using the I2C, do you add the external pull up resistor or not?

   If yes, it will cause the two pin to 1 during boot, then boot maybe failed.

   0.38ms maybe not enough to enter to the customer app main.

   Now, when you do it, do you meet the boot issues or not?

Best Regards,

Kerry