Jump to ISP bootloader from application mode

[tks11111]

Hi,

Is there a way to jump to ISP bootloader mode from application mode without pressing the ISP button?

I tried the method mentioned in Entering ISP mode from application code in LPC55 - NXP Community, but none can force the LPC5528 and LPC55S28 into ISP mode.

My IC Device ID is 0xA010111C and 0xA010119C.

Let me know if there is anything I need to provide.

Thanks.

[tks11111]

Hi Alice,

The date code is 1927.

I also tried the method you provided, but the chip kept resetting and could not enter ISP mode.

Do I need to erase the app code before calling NVIC_SystemReset?

BR,

Peter

[nxf64834]

Hi,

Please refer below snippet from Errata for tried and tested method to enter ISP mode from application.

Thanks.

[tks11111]

Hi,

As we discussed previously, I tried this method and it did not work.

That is why I asked for another method to enter ISP mode from the application.

The workaround method I used was to wire a capacitor between P0_5 and GND, and set P0_5 to digital low before I called NVIC_SystemReset(). This way, the IC detected P0_5 low and entered ISP mode.

However, this method had some flaws because we might need to add a capacitor and wait for the discharge time.

I wonder if there is any method that can enter ISP mode without adding any components.

Thanks.

BR,

Peter 

[Alice_Yang]

Hello @tks11111 

I don't think need erase code.

Could you please first use ISP pin to test, whether your chip can enter ISP mode successfully, and can communication with PC through UART port or USB?

BR

Alice

[tks11111]

Hi Alice,

I can enter ISP mode on my chip by using the ISP pin. I also use USB1 as a communication port with my PC.

After the chip enters ISP mode, the PID/VID changes.I use the blhost tool to upload my FW bin file, and the chip works correctly after it returns to app mode."

BR,

Peter

[Alice_Yang]

Hello @tks11111 

How about have a pullup resistor connected to the P0_5 pin ?

https://community.nxp.com/t5/LPC-Microcontrollers/LPC5526-run-isp-bootloader/m-p/1609563  

BR

Alice

[tks11111]

Hi Alice,
We added a capacitor between pin0_5 and GND, and set pin0_5 to digital low before we reset the IC.
After doing this, the IC could enter ISP boot mode after the reset.
I wonder if pullup resistor can have the same result?

BR,
Peter

[Alice_Yang · Accepted solution]

Hello @tks11111 

1) "We added a capacitor between pin0_5 and GND, and set pin0_5 to digital low before we reset the IC.
After doing this, the IC could enter ISP boot mode after the reset."

->> This is use  ISP pin entered ISP mode.

2)Pull up PIO0_5 is when using code jump. While I haven't test on my side, because there is no chip with code 1927 on my side. Just other customer's experience. You can test.

BR

Alice

[Alice_Yang]

Hello @tks11111 

What is the date code of your device? You can find on marking of your chip.

And there is issue with  date code 2101 (yyww) onward, detail:

https://www.nxp.com.cn/docs/en/nxp/errata/LPC55S2x_LPC552x_ES.pdf 

BR

Alice