TMS320F28377S: Change the boot pin

Angela Zou

Part Number: TMS320F28377S

Hi experts,

In the F28377 application, we need to use the EMIP1 function. It occupies the F28377 boot pin GPIO72. So we changed the GPIO72 boot function to GPIO142 (previously GPIO72 and GPIO84 boot, Now GPIO142 and GPIO84 boot). But after changing the boot pin, there is a certain probability that after the hardware reset or programing to flash, it will not boot. The status of GPIO72 is still relevant, please help analyze this issue, thank you!

Here is the register value(read from ccs):

Z1_BOOTCTRL Register：0x8F55FF5A

Z2_BOOTCTRL Register：0xFFFFFFFF

over 2 years ago

0 Hareesh Janakiraman over 2 years ago

TI__Guru* 94005 points

Angela,

There is no "EMIP1" in this device. Perhaps you were referring to EM1D12. Can you provide a scope capture of GPIO142 & GPIO84 pins while powering up? Please capture -XRS and VDDIO as well.

0 Angela Zou over 2 years ago in reply to Hareesh Janakiraman

TI__Prodigy 675 points

Hi Hareesh,

After the GPIO72 boot function has been modified to GPIO142, if set the GPIO72 to be low, the issue will happen in approximately 10 hours; if set the GPIO72 to be high, it will not happen any more.

The XRS and VDDIO waves are as below after normally power up. CH1(yellow)---XRS，CH2(green)---GPIO142, CH4(blue)---GPIO84.

0 Hareesh Janakiraman over 2 years ago in reply to Angela Zou

TI__Guru* 94005 points

Sorry I don’t understand. Boot function has been changed from GPIO72 to GPIO142. So, technically GPIO72 should not have any influence over the boot process anymore. But you are saying if GPIO72 is low, issue happens once every 10 hours, but issue is never seen when GPIO72 is high.

The scope waveform is not clear. I need to see the following 4 channels clearly, without any overlap: VDDIO, -XRS, GPIO142 and GPIO84.

0 Angela Zou over 2 years ago in reply to Hareesh Janakiraman

TI__Prodigy 675 points

Hi Hareesh,

It is so strange that the boot process is still related with the state of GPIO72.

I will ask them to retest.

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TMS320F28377S: Change the boot pin