topic Re: LPC55S16 64-pin Processor Verification in LPC Microcontrollers

LPC55S16 64-pin Processor Verification

Matthias9265 — Tue, 31 Jan 2023 22:42:43 GMT

Hi All!

I'm developing a board using the LPC55S16JBD64E and I've run into some issues with validating the device is powered up. Does anyone have a particular examples or insight of methods to verify the processor is successfully powered?

I've used the EVK and read its device signature using Flash Magic through USART using a serial-USB cable. If my understanding is correct, this should be a valid method, but so far unsuccessful.

The signal coming out of pin 31 (LX) appears correct on the scope (similar to the output on the EVK).

Both Oscillators are running as well.

Any ideas?

Thanks!

Re: LPC55S16 64-pin Processor Verification

Alice_Yang — Thu, 02 Feb 2023 08:46:22 GMT

Hello @Matthias9265 ,

You can measure the voltage from below two detection points：

Point 1 is input, should 1.8-3.6V, usually 3.3v.

Point 2 is output of DCDC, should 1.1V.

Alice

Re: LPC55S16 64-pin Processor Verification

Matthias9265 — Thu, 02 Feb 2023 21:10:47 GMT

Thanks for the response,

Those voltages are reading correctly but I am still unable to read a signature from the device and RESETN and ISP is pulled high.

A little more information:

Serial cable connects through a level shifter when reading the EVK device from JP3 Serial Port. My understanding is that this is the USART0. On the 64-pin, I am connecting to P0_29,30 for RX and TX respectively.

Port0_5 is ISP

Pulling ISP low and resetting (pulling RESETN low) should put it in ISP mode and default these pins to their ISP mode condition, but I don't get any response from the device read.

Re: LPC55S16 64-pin Processor Verification

Alice_Yang — Mon, 06 Feb 2023 08:11:53 GMT

Hello @Matthias9265

When in ISP mode, P0_29 as UART0_RX, P0_30 as UART0_TX, so connect the TX of your USB-UART transfer to P0_29 of your chip, and RX to P0_30.

Alice