LPCXpresso4337 UART ISP Not working

[emantec]

Hi,

I'm fairly new to this so I apologise in advance if I've missed something obvious. 

I have a LPCXpresso4337 (18S37) dev board and I'm attempting to get it to boot into ISP via UART with no luck. 

The manual states 

Boot mode  P2_9   P2_8   P1_2   P1_1   Description
USART0     LOW    LOW   LOW   LOW   Boot from device connected to USART0 using pins P2_0 and
P2_1. For flash parts, enter UART ISP mode.

As far as I can tell this just requires JP3 to be bridged and all pins should then be low and it'll boot into ISP UART, however the BOOT0_LED indicator just blinks as boot failed. Attempting to synchronise through UART does nothing. 

The board is brand new and hasn't been programmed for anything but some LPCXpresso IDE examples so BOOT_SRC bits should be 0.

Any help would be appreciated. 

[emantec]

Bump

[xiangjun_rong]

Hi, Tim,

pls check the PIO2_7 pin logic when you power up, when the PIO2_7 pin is High, the chip will boot from internal flash and run the application code automatically. I think it is the case you have now.

When the PIO2_7 pin is LOW, the chip will enter boot mode and wait the Uart0 signal when all the P2_9, P2_8, P1_2, and P1_1 are LOW.

Pls refer to the part I copied from 5.3 Functional description in UM10503.

"

For flash-based parts, the part boots from internal flash by default (boot pin P2_7 is
HIGH). If the boot pin is sampled LOW on reset, the boot source is determined by the
setting of the OTP or the states of pins P2_9, P2_8, P1_2, and P1_1. For details of the
boot process for flash-based parts, see Figure 15.

"

Hope it can help you

BR

XiangJun Rong

[emantec]

P2_7 is connected to the ISP switch (SW2)? No?

Holding ISP whilst board is reset still results in a failed boot. 

Can someone please specify the exact steps on how to get this board into ISP mode? I'm at a loss here.

[xiangjun_rong]

Hi, Tim,

First of all, can you post the schematics of LPCXpresso4337 so that I can check the P2_7 pin switch or button.

Secondly, I suppose that you can use FlashMagic tools to download code to flash of LPC4337 with uart under ISP mode.

This is FlashMagic tools link:

https://www.flashmagictool.com/

I think it supports LPC4337.

Hope it can help you

BR

XiangJun Rong

[emantec]

Schematic can be found here

https://www.nxp.com/downloads/en/schematics/LPCX4337_V3_Schematic_RevA3.pdf

I've already tried FlashMagic which just fails on AutoBaud as there's no response from the board. 

[xiangjun_rong]

Hi,

I think it is a bit complicated that you want to use uart0 to boot up, you have to configure the board so that it can boot from uart0.

If you want to boot from uart0, all the P1_1/P1_2/P2_8/P2_9 must be low.

the P1_1-BOOT0_LED-SSP0_MISO must be LOW, you can close the pin 3 to pin5 of the J3 connector to make it low. You have to close the JP3 so that P2_8-BOOT2_TRGT is low.

Regarding the UART0 signal, if you J5 USB connector, the PC will enumerate the J5 USB as a CDC port and give a virtual port, you can use the port as UART0 to download code. If you do not connect the J5 USB connector, you have to connect the UART0 via  P4 connector.

After the above configuration, you can hold on the SW2 during the power power off then on, after a while, release SW2, then check if you can use FlashMagic to communicate with the LPC4337.

Hope it can help you

BR

XiangJun Rong

[emantec]

Thanks for taking the time to help but unfortunately still no luck, the PWR LED is active but the boot LED shows nothing and no response from FTDI UART. Using the USB no COM device is visible either.

This is my setup to confirm (With SW2 held on reset) 

[xiangjun_rong]

Hi, Tim,

It is unusual that you can not see the CDC virtual COM port if you connect the link USB port.

Anyway, can you use Keil or MCUXpresso tools to develop and download code to LPC4337 with SWD or JTAG port?

This is the LPCOpen package, you can download the project and try to compile and download code via SWD or JTAG.

https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mc...

Hope it can help you

BR

Xiangjun Rong

[emantec]

I can build and run code fine using the USB and LPCXpresso, the issue is that I want to use the ISP via UART...

Running the "usbd_rom_cdc_uart" project from LPCOpens creates the COM port in device manager but I don't see how this helps the ISP problem? 

[xiangjun_rong]

Hi,

On the LPCXpresso4337, if you open JP6 jumper, can you see the CDC USB port on the PC device manager?

BR

XiangJun Rong

[emantec]

Open? I assume you mean bridge, if I do that to force DFU mode then I can see a COM port in device manager. 

Without bridging I only see the COM port when running the previously mentioned project. 

[xiangjun_rong]

Hi,

I think you can download code to flash in ISP mode with the enumerated COM port.

BR

XiangJun Rong