MK60DN512VLQ10 Reset pin

[nbjasani]

Hi there,

 I have used mk60dn512vlq10 device in our custom board. Problem is, mk60dn512vlq10 mcu kept reset pin to low at power up and it continue low. Due to that i cannot able to download application program. I have attached reset connections image. Where R10 = 10K resistor and C9 = 10uF Ceramic Capacitor. I also have gone through "MK60DX256VLL10 RESET PIN" thread in this forum and i tried all which was mention in that forum, but still problem persist.

  Please help.

Regards,

Nandish Jasani.

[Robin_Shen]

Hi Nandish Jasani,

Although you say you have tried all the tips mentioned in that post, I still want to confirm:

Make sure all power pins are properly connected (including VDDA VSSA VREFH VREFL)
How about USB VREGIN VOUT33 pins?
Make sure the voltage at NMI_b pin is high
Observe the waveform of the RESET_b pin through the oscilloscope, there should be a pulse signal instead of being low all the time
Do you have a debugger for PEMicro, tell me the version
How did you constantly power cycle the microcontroller?(PEMicro debugger should always connected)
Do you have Segger JLink? You can refer to this: Communication error while accessing MDM-AP.

Best Regards,
Robin
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[nbjasani]

Hi Robin,

    Thank you for your reply.

1.All power pins are connected properly including VSSA VDDA VREFH and VREFL. We have 3V reference IC connected for Vrefh and Vrefl.

2. VREGIN and VOUT33 are kept open.

3. NMI_b/EZP_CS_b is kept open.

4. Yes we are using PE Micro and its Multilink Universal Rev D (PEM7C8B01).

5. I dont have Segger JLink.

6. Regarding power cycle: MCU Reset pin is continuously low after power up and without connecting PE Microdebugger.

7. We have checked Reset pin of MCU and its being low all time. No pulse signal only low all the time.

Best Regards,

Nandish Jasani.

[Robin_Shen]

3. NMI_b/EZP_CS_b is kept open.
Pull up NMI_b, make sure it's high voltage

6.PEMicro debugger should always connected. Just power up and power off the K60

8.Check the circuit of debug interface:

[nbjasani]

3. I checked in oscilloscope at pin NMI_b/EZP_CS_b: It shows 3.3V Constant due to internal pull up.

6. I did multiple power cycles with debugger connected, but still problem persist.

8. JTAG_TMS = Pullup = 3.28V (Measured Value)

    JTAG_TCLK = Pulldown = 62mV i.e. 0V.(Measured Value)

    JTAG_TDI = Pullup = 3.27V.(Measured Value)

    JTAG_TRST = Pullup = 62mV i.e. 0V.(Measured Value)

Note: After assembling PCB with components, first we only give VDD and VSS, VDDA and VSSA is not supplied at that time. This can create problem? Is there any power sequence require between VDD and VDDA?

Regards,

Nandish Jasani.

[Robin_Shen]

VDD and VDDA should be power at the same time:

[nbjasani]

Hi,

   We are ensured that VCC an VCCA are powered on same time. In my schematic JTAG Reset pin is kept open and according to datasheet it should be pull up, But after power up JTAG Reset pin is low all the time. Pin no. 55 in MK60DN512VLQ10. Is this will effect MCU Reset pin? 

Regards,

Nandish Jasani.

[Robin_Shen]

Note that the nTRST signal is initially configured as disabled. So it's not the issue. And you should be able to connect MCU by SWD interface too.

Note: After assembling PCB with components, first we only give VDD and VSS, VDDA and VSSA is not supplied at that time. This can create problem?

Since your initial power supply doesn't meet the datasheet requirements, I'm not sure if that's the problem. I wonder if you have other circuit boards that have not been soldered, try to supply power at the same time to check if the problem still exists.

Hold the RESET_b(pin 74) low, are you able to connect the MCU by Multilink Universal?(Please update the driver https://www.pemicro.com/products/product_viewDetails.cfm?product_id=15320180&productTab=4) It is recommended to submit technical support to PEMicro to ask if there is a method similar to JLink to access the MDM-AP status and control registers.

[nbjasani]

Hi,

     "I wonder if you have other circuit boards that have not been soldered, try to supply power at the same time to check if the problem still exists".

    I Populated new board and in that problem is solved. We moving forward in that board and simultaneously we will replace new microcontroller IC with existing IC in problematic board. 

Regards,

Nandish Jasani.