SJA1110 Use Case Configuration

[Wobaffet]

We are planning to integrate the SJA1110 with the i.MX8MP to support 5x T1 PHYs. During evaluation, we have encountered uncertainties about how to properly implement and boot the switch firmware alongside the i.MX8MP. Based on the documentation, there appear to be two options for running applications on the SJA1110:

1. SDL – loading over SPI from an external controller (i.MX8MP in our case).

2. NVM boot – using an external flash to store the application image to be executed by the SJA1110.

We need clarification on the following points:

• Do we need to develop a custom M7 application to run on the SJA1110, or are there ready-made application binaries provided by NXP that we simply need to load via SDL or NVM?
• If SDL is used, does the application need to be reloaded on every boot, or does the internal MCU of the SJA1110 have any flash capability to retain the firmware?
• What is the typical size of an application binary, so we can estimate boot-time overhead if we use SDL?
• Since the SJA1110 exposes JTAG pins, can we flash the application directly in mass production, thereby avoiding external NVM? (leaving spi pins floating)
• If so, is it possible to permanently store the firmware this way and operate directly with the drivers provided in the BSP?
• Apart from integrating the SJA1110 drivers that are already part of the latest i.MX8MP BSP, what additional software development is required on our side in order to operate the T1 PHYs through the SJA1110?

Thanks! Best Regards.

[JorgeCas · Accepted solution]

Hello,

1. Depending of the application, would be better to use the second option since the PHY driver will initialize it.

2. 4. 5. JTAG flashing is supported for the device. There are tools like this than can flash the internal MCU of the SJA1110 using JTAG.

3. The firmware binaries are typically in the hundreds of kilobytes range.

6. You may need to configure your device tree and SPI parameters, please take a look in the next link.

Best regards.

[Wobaffet]

Hello,
Thank you for answering all the questions.
I just want to clarify, internal MCU doesn't have any internal flash.
If we use SDL, we have to load binaries on each boot from host to the SJA1110.
Also, could you please attach the link again? We're not able to see it.

Thanks!

[Wobaffet]

reminder.