Problem when programming for stm32f765

[Huy Nguyen]

Posted on June 17, 2018 at 12:17

Hi, has anyone worked with stm32f765 ? I'm now working with it in my project. I created my own PCB to test this stm32f7  , I have try  many time but anytime I test it, the stm32f7 always be damaged because I found that Vdd and Vss in my PCB is connected (I have checked this before I tested). Obviously, I test it by using swd through st link v2. First time, the programmer (Keil C v5) can detect stm32 but when I load my code to the chip, it reported that loading successful but verify fail. I disconnected my PCB and when I checked, I saw that Vdd and Vss are connected. My hardware always follow the datasheet, I sent my PCB design to others to check but they didn't see any problem and I myself check it many time and I think it's a corrected PCB. I don't want to damage any stm32f7 because I just have 1 chip to test the next time. I will be very grateful if someone can help me solve this problem. 

I have attached an image of my schematic.

Thanks ! 

[Tesla DeLorean]

Posted on June 17, 2018 at 12:41

Unless you're injecting a large voltage I don't see an immediate issue with the design portion shown.

There could be issues with other components not shown.

You should go over the pin assignments and numbering to sanity check that.

Check voltage at VCAP on most recent board.

Remove broken F7, or populate a board with everything but the F7, and make sure all the pin voltages are as expected and input/output senses aren't mixed up.

Check all the ground pins, and make sure there aren't any disconnected islands. Check the netlist thoroughly.

[Huy Nguyen]

Posted on June 17, 2018 at 12:58

Hi ! Actually, I use my STM32F4 Discovery board with SWD and power on this board to test my STM32F7 board so I don’t think I injected a large voltage. I checked the voltage in Discovery board, it is 2.96V. I will check the VCAP voltage in my next PCB. But I think my issue is that when I program for it, I get a notice that programming successful but verify fail from Keil C so I think the problem related to my software, not my hardware. Do you have any ideas ?

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________________ Attachments : 1A524422E1024B7683FFC2D1DCD0D406.png : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HxUP&d=%2Fa%2F0X0000000ayk%2Fij8aFuCwRtS1OrjCS5MqY2IpMshPF1Dk6HFbFtVOzl4&asPdf=false

[henry.dick]

Posted on June 17, 2018 at 16:36

'

I will be very grateful if someone can help me solve this problem.'

1. check your schematic vs. the datasheet and make sure that the pins are correct;

2. check your pcb library and make sure that the pins are correct;

3. measure Vdd-Vss on empty / unpopulated PCBs;

4. populate the passive and measure Vdd-Vss on the PCB. it should go from 0R to infinite, unless you have resistors from Vdd-Vss;

5) populate the chip. make sure that its orientation is correct; and there is no shorts between pins;

6) power up the PCB with a large value resistor - I would start with 1K. measure the voltage drop over that resistor. go back to 1 if it is unexpected (too large).

7) gradually change the resistor to smaller values and make sure that the current consumption remains expected.

8) power up the chip / pcb without any resistor + an ammeter in serial. make sure that the current consumption is as expected.

9) load up the simplest and proven code and observe the current consumption.

10) load up the real code and go from there.

[Tesla DeLorean]

Posted on June 17, 2018 at 16:23

Perhaps power from a bench source and observe current drawn.

Software you're downloading should not cause the part to failure during verify.

If you have code reassigning the debug pins you could try pulling BOOT0 high so it doesn't run your code.