AM6442: Does CPTS rely on any peripheral?

Zekun Bai

Part Number: AM6442

Tool/software:

Customer met a issue on their own board and want to check with TI.

Phenomenon:

After the network port card is unplugged and the board is powered on, there is no /dev/ptp1 device.
Plug in the network port card and the device is started, there is a /dev/ptp1 device.

Purpose:

Whether there is a phy card or not, the /dev/ptp1 device is required.

Question:
Does the CPTS of cpsw depend on other peripherals of CPSW, and can it be used independently?
If it can be used independently, what should to do to enable this? If not, please explain why?

Regards

Zekun

over 1 year ago

0 Nick Saulnier over 1 year ago

TI__Guru** 101700 points

Hello Zekun,

The CPTS is basically a fancy counter that can be used to timestamp signals and generate sync pulses. Different TI processors can have different numbers of CPTS instances, which can inside a specific peripheral (like CPSW or PCIE), or just somewhere inside the processor for general purpose use.

The CPTS inside the CPSW peripheral allows the CPSW to precisely timestamp Ethernet packets, which enables cool stuff like PTP.

For more details about using PTP on AM64x, refer to the Linux SDK docs here:
https://software-dl.ti.com/processor-sdk-linux/esd/AM64X/10_00_07_04/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-PTP.html

You can find links to other kinds of Ethernet TSN here:
https://software-dl.ti.com/processor-sdk-linux/esd/AM64X/10_00_07_04/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-TSN.html

Regards,

Nick

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AM6442: Does CPTS rely on any peripheral?