Hello, ed@modk.it
Please note that for the LPC devices, the ROM bootloader is called ISP.
1) The ISP interface for the LPC824 only supports USART. Here
you can take a look at the default and available pins

From LPC82x UM.
Those pins are configured automatically when entering to ISP (ROM bootloader ) after POR or reset
2) Since the ISP comes preloaded on ROM we don't provide code for the ISP itself.
In this case, you will need to adapt your design to use those pins.
.
Please, let me know If I can help you further!
Best regards, Diego.
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------