STM32L433RCT6 - Which GPIO pins do I need to use for flashing using ST Link / Segger J-Link / UART / USB

[johngj]

I am designing my own PCB which uses the STM32L433RCT6

I want to ensure I have the necessary GPIO pins going to a connector so that I can flash/debug using the following interfaces:

Below are the GPIO pins I have brought out to connectors, have I missed anything or got anything wrong ?

1. ST link: For flashing and debugging during development

I have currently routed the following pins to a 6 pin connector:

• SWDIO (PA13)
• SWCLK (PA14)
• NRST
• BOOT0 (PH3)
• GND
• +3.3V

2. Segger J-Link: For flashing and debugging during development

I have currently routed the following pins to a 6 pin connector:

• SWDIO (PA13)
• SWCLK (PA14)
• NRST
• BOOT0 (PH3)
• GND
• +3.3V

3. UART: For firmware updates

I have currently routed the following pins to a 4 pin connector:

• LPUART Tx
• LPUART Rx
• GND
• +3.3V

Is LPUART suitable or does it need to be USART ?

4. USB: For firmware updates

I have currently routed the following pins to a USB connector:

• USB D+
• USB D-

In STM32CubeIDE, the SYS configuration has serial wire, JTAG (4 pins) and JTAG (5 pins).  

I noticed that JTAG (4 pins) uses an extra pin for "SWO" (PB3) and JTAG (5 pins) uses an extra pin "SYS_JRST" (PB4).

Would I need these pins too ? 

[mƎALLEm]

Hello,

You need to check the AN2606 for the ST bootloader resources.

You can't use LPUART. Please refer to the table 152 for the bootloader resources available for USART / USB in STM32L43x.

For STLINK/JLINK, please refer to any Eval board schematics example: STM32L476G-EVAL.

PS: in next time it's recommended to separate the questions in multiple thread. It's hard to manage many questions in the same thread.

For example, you may ask: ST bootloader question in a thread and the STLINK/JLINK in another thread. Thank you.