S32GのトピックRe: S32 Boot from Serial RCON

S32 Boot from Serial RCON

pcentauri92 — Fri, 30 May 2025 07:38:17 GMT

Hi NXP Community,

I am trying to boot the S32G-VNP-RDB3 board using the serial RCON mode to avoid using the DIP switches on the board. As mentioned in the S32G3 Refernece manual, Serial RCON requires an external serial EEPROM that communicates with the chip via I2C. I want to use an external MCU in my design to mimic the EEPROM.

As mentioned in the document, I have set the RCON[8] pin to high using the SW5[1] using the DIP switch on the board.

As the I2C port required for RCON serial boot (RCON[7] and RCON[8] connected to I2C0) are not exposed by the board, I have soldered wires as shown in the attachment to the two open ports connected to the SerDes Clock as they are not used by it. I verified that I2C0 is required by the RCON pins following the schematics.

I have not changed any of the other DIP switches and left them in their default configuration. Now, when I connect a logic analyzer to the I2C0 pins that I have soldered, I get nothing when the S32 boots. I verified that the I2C line that I soldered work as they show data on them once the S32 boots in normal mode.

Some clarifications would be helpful here.

1. The reference manual mentions that the EEPROM or the MCU in my case needs to act as a slave with the address (0xA0) but the Serial EEPROm in the schematics show a different address (0x 50). Should I use 0x50 as the I2C address for my MCU?

2. Should all the DIP switches be set to low state and just the SW5[1] (RCON[8]) to high for the serial RCON boot mode?

3. Should any Pinmux be changed to access the RCON[7] and RCON[8] on the I2C0 lines?

4. AN13456 mentions that RCON[8] and RCON[9] need to be used for this mode which is clearly different from what is mentioned in the S32G3 reference manual. Which one is correct?

4. Is there any other configuration that I have missed apart from what is already mentioned above?

Thank you.

Re: S32 Boot from Serial RCON

Joey_z — Fri, 30 May 2025 10:31:49 GMT

hi,pcentauri92

Thank you for contacting us.

The first question. I think the 0xA0 mentioned in the manual is the write address in the 8-bit address format, while the 7-bit address of the actual device is 0x50. The two should be equivalent.

For the remaining questions, as there are many of them, I will summarize them for you. And I will reply to you as soon as I have the results.

Hope it can help you.

Joey

Re: S32 Boot from Serial RCON

pcentauri92 — Mon, 02 Jun 2025 09:08:57 GMT

Hi @Joey_z following up on the EEPROM that is on the S32G3-VNP-RDB3, the schematic shows that it is not available to be used through the OS as shown here

The Pin mux needs to be changed for I2C0_SDA PB_00 and I2C0_SDA PB_01 to be used with I2C0 as it is used by the CAN and UART0 interface. The same is confirmed through the OS

However, this still does not explain why the Bootrom of the S32 does not start the I2C communication on I2C0 when it starts to boot.

Please let me know if you have found any solution to this issue.

Thanks.

Re: S32 Boot from Serial RCON

Joey_z — Tue, 03 Jun 2025 02:45:44 GMT

hi，pcentauri92

Thank you for your information.

1.Use the serial RCON, need to set the RCON[8], and does not require DIP switchs.

2.The RCON8 and RCON9 mentioned in Document AN13456 should represent RCON[7] and RCON[8] respectively. From the content of the manual and the schematic diagram, it can be determined that they are RCON[7] and RCON[8].

3.The I2C0(PB_00/PB_01) has connected to the AT24C01 EEPROM device on S32G-RDB3.

4. You can refer to this configuration for setting serial RCON. In serial stage, you can check whether the IIC communication has been established by looking at the device address sent by the Master.

Hope it can help you.

Joey