TDA4VM: How to sync TDA4-2's hw clock with TDA4-1 as both TDA4 are connected in one system

vishal trivedi

Part Number: TDA4VM

Tool/software:

refering to below forum TDA4VM: I have some questions about time synchronization applications - Processors forum - Processors - TI E2E support forums , i would like to know How to sync TDA4-2's hw clock with TDA4-1 as both TDA4 are connected in one system

11 months ago

0 Josiitaa RL 11 months ago

TI__Mastermind 40966 points

Hi,

Our expert is on business travel until Sept 16th. Please expect delay in responses.

Regards,

Josiitaa

0 Tanmay Patil 11 months ago in reply to Josiitaa RL

TI__Mastermind 38740 points

Hi,

The way to do time sync over network would be to use PTP.

Please see the demo and documentation for PTP on TDA4 here.

Regards,
Tanmay

0 vishal trivedi 11 months ago in reply to Tanmay Patil

Prodigy 100 points

Hi,

Could you please provide additional details on:

Specific configuration steps for PTP on TDA4.
Latency and jitter handling
Any potential challenges or performance considerations we should be aware of
Best practices for optimizing time synchronization in a networked environment using PTP.

0 Tanmay Patil 11 months ago in reply to vishal trivedi

TI__Mastermind 38740 points

Hi Vishal,

vishal trivedi said:
Specific configuration steps for PTP on TDA4.

The configuration and commands for running PTP are mentioned in the documentation attached : https://software-dl.ti.com/jacinto7/esd/processor-sdk-linux-jacinto7/10_00_00_08/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-PTP.html

See the "3.2.2.10.3.3.2.1.2.Setup" and "3.2.2.10.3.3.2.1.3.PTP with Ordinary Clock (MAC mode)" section

vishal trivedi said:
Latency and jitter handling

TDA4 SoC have physical timestamping capabilities which help reduce the effects of latency and jitter.

vishal trivedi said:
Any potential challenges or performance considerations we should be aware of

The ptp daemon running on both SoC and external device is very thin and does not consume a lot of resources in either cpu or network bandwidth.

vishal trivedi said:
Best practices for optimizing time synchronization in a networked environment using PTP.

Use hardware timestamping on the external device as well. For a demo, you can try with two EVMs.

Note: PTP will synchronise the CPTS with external clock. To sync the system clock (clock used by linux), you have to use "phc2sys" in addition to ptp to sync system clock with CPTS clock. example command : "phc2sys -c CLOCK_REALTIME -s eth0 -O 0 -m" Please select the source ("-s" flag) appropriately.

manual page for phc2sys : https://linuxptp.nwtime.org/documentation/phc2sys/

Regards,
Tanmay

0 vishal trivedi 11 months ago in reply to Tanmay Patil

Prodigy 100 points

The support for CPTS module can be enabled by Kconfig option CONFIG_TI_AM65_CPTS or through menuconfig tool.

0 vishal trivedi 11 months ago in reply to vishal trivedi

Prodigy 100 points

The support for CPTS module can be enabled by Kconfig option CONFIG_TI_AM65_CPTS or through menuconfig tool.

we require CPTS module for QNX can you provide the same ?

0 Tanmay Patil 11 months ago in reply to vishal trivedi

TI__Mastermind 38740 points

Hi Vishal,

Can you please contact QNX for the same. The io-sock based QNX native driver for CPSW is managed by QNX. They would have the information you need.

Regards,
Tanmay

0 vishal trivedi 11 months ago in reply to Tanmay Patil

Prodigy 100 points

FIG: Two TDA4VM CONNECTED IN SYSTEM

Q1) Relation of CPTS & PTP ?

Q2) In above figure where does CPTS will fit

q3) Is local time the GTC ? i.e using vision apps, GTC clock is already enabled only by one core and rest of the cores just use it to get the current ticks.

Detail process to ensure QNX of ZC1 (TDA4VM) & ZC2 (TDA4VM) connected in same system should have sync time .

0 Tanmay Patil 11 months ago in reply to vishal trivedi

TI__Mastermind 38740 points

Hi,

vishal trivedi said:
Relation of CPTS & PTP ?

CPTS will do the hardware time stamping for the packets. These timestamps will be used by PTP stacks for sync.

vishal trivedi said:
In above figure where does CPTS will fit

It will be controlled by QNX. QNX will configure the CPTS and also run PTP stack.

vishal trivedi said:
Is local time the GTC ? i.e using vision apps, GTC clock is already enabled only by one core and rest of the cores just use it to get the current ticks.

No, the local time in this case could be two things, either CPTS clock or A72 internal clock . I am not sure up to what level of sync is supported with QNX.

vishal trivedi said:
Detail process to ensure QNX of ZC1 (TDA4VM) & ZC2 (TDA4VM) connected in same system should have sync time .

For the details, QNX would be able to help you with the steps for setting this up.

Regards,
Tanmay

0 vishal trivedi 11 months ago in reply to Tanmay Patil

Prodigy 100 points

who enables HW time stamping (CPTS connect to Ethernet )? PTP Leader and follower daemon ? Ethernet driver ? FW application ?
what is accuracy on counter before the roll over event is created ?
can A complete 1588 clock sync solution applicanle to TI TDA4VM . Attached is snip from TI 1588_K2_HW_SW overview (1588_K2_HW_SW_Overview)

0 Tanmay Patil 11 months ago in reply to vishal trivedi

TI__Mastermind 38740 points

Hi,

vishal trivedi said:
who enables HW time stamping (CPTS connect to Ethernet )? PTP Leader and follower daemon ? Ethernet driver ? FW application ?

This would be done by CPSW driver.

vishal trivedi said:
what is accuracy on counter before the roll over event is created ?

Th sync is usually accurate upto few tens of nanosecond.

vishal trivedi said:
can A complete 1588 clock sync solution applicanle to TI TDA4VM . Attached is snip from TI 1588_K2_HW_SW overview

Yes, this is present on linux. For QNX, I can't comment. For QNX, you can do an initial check here: https://software-dl.ti.com/jacinto7/esd/processor-sdk-qnx-jacinto7/10_00_00_04/exports/docs/qnx_sdk_components_j721e.html#cpsw2g-devnp-driver.

It seems PTP with hardware timestamping is enabled. But I still cannot comment on the complete stack support of what you want.

Regards,
Tanmay