TMS320F28335

Hello, there is still a question to ask, TMS320F28335 boot pin GPIO84, 85, 86, 87 externally connected to the pull-up resistor 5k ohms, the DSP power-on reset chip completes the reset, that is, the low level becomes high 。The oscilloscope found that the boot pins GPIO84, 85, 86, and 87 all have a low level of nearly 300ms, and then become high, causing the DSP program to fail to load and run. I would like to ask, from the manual, the BOOT pin should be an input when the reset is completed. How can it become a low level when there is a pullup on the outside?

In the figure below, blue is reset and purple is BOOT GPIO85 pin level.

To debug this further, I need the following:

The schematics of your design. You can share this with me privately. No need to post it on e2e. (I will send you a friendship request)

A scope capture that clearly shows the following signals. Please separate the signals on the screen and don’t let them overlap each other:

1.8v, 3.3v, -XRS, GPIO85

You can help me see the principle design of the DSP emulator. The RST pin does not have a pull-down resistor. Will it cause the DSP program to be reset and not running? Is the pull-down resistor necessary? What role?

The 3.3V and 1.9V power supply circuits are as follows:

The images are not showing in the post. Please use a different method to attach them. 

You can help me see the principle design of the DSP emulator. The RST pin does not have a pull-down resistor. Will it cause the DSP program to be reset and not running? Is the pull-down resistor necessary? What role?

My related circuit schematic is in the attachment。

The figure you have included shows nothing useful. Unless you send me the schematics that clearly shows all the circuitry related to the 1.8v/3.3v generation, -XRS handling and the scope capture I had requested in my 6/6 5:43 AM post, I cannot help you further. Sorry.