LPC54606 : I/O state in IAP (Reinvoke ISP)

[karimboallal]

Hello,

I'm working with a LPC54606J512BD208 and I'm using the IAP command "Reinvoke ISP" to update the firmware.
When I set some outputs to '0' state, the state is maintening during isp mode while with somes other output, the state change to default state (input pull-up).
For example the state is maintening with PIO4_15, PIO2_22, PIO2_23, PIO3_29 but not with PIO1_19, PIO1_20, PIO1_16, PIO0_19.

I sense that it's depend of the port number... But nothing is specified either into datasheet nor into user manual except that default state of all pins is input pull-up (except I2C open drain pins).

Someone know what is the criteria to select a pin with its state is maintening during isp mode?

Best Regards,

Karim.

[jeremyzhou]

Hi Karim BOALLAL,

Thank you for your interest in NXP Semiconductor products and
for the opportunity to serve you.
Whether you want the state of all pin stick to same when the MCU enter the ISP mode via the Reinvoke ISP command.
If yes, in opinion, I'm afraid it's almost impossible because we don't know the exactly code in the ROM bootloader, it may initialize some pins during the code.

Have a great day,
TIC

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[karimboallal]

Hi jeremyzhou ,

Thank you for your prompt response.

I don't want the state of all pin stick to same, but I want to know which pins are not intialized (not change) when the MCU enter the ISP mode.

I don't have custom bootloader so it 's the "original" bootloader.

Is it possible to tell me which pins are not initialized during bootloader?

Best Regards,

Karim.

[jeremyzhou]

Hi Hi jeremyzhou ,

Thanks for your reply.
To be honest, it's not 100% sure.
In my opinion, the ROM bootloader will initialize the pins which are determined by the selected ISP type, in another word, the ROM bootloader will initialize the pins of the related peripheral after entering ISP mode.

Have a great day,
TIC

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- We are following threads for 7 weeks after the last post, later replies are ignored
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