TSC Controlled Signals

Technical reference manual section
“TSC Controlled Signals” indicates that it is possible to generate some output waveforms that are inherently driven from the main TSC.
It details the register settings to generate the 4 possible output waveforms which appear to be exactly what I require to be able to generate a couple of square wave outputs that are synchronised to the internal Main TSC.

What I can’t understand is how setting the registers to generate these is routed to the appropriate output pin.

The TRM states:
“In the SoC, the TSC block generates four independent signals, that are broadcast to a small number of pads. The target pads must use the standard pinmux logic, ideally with one available port or replacing an existing but not used port, as shown below. The first generator broadcasts its signal to four pins with stringent timing skew requirements, eliminating an external buffer. Other generators sent this signal to a single pin only.”

the TRM reference above to “…broadcast to a small number of pads…” would suggest that there may be some restrictions on which pins can be used, but when I look at the descriptions for the pinmux & GPIO sections in the TRM I can’t see how to route the TSC Controlled Signals to output pins.

Hi, you can use the pins with “PWM” in SFIO column of pinmux sheet. Jetson Orin NX Series and Jetson Orin Nano Series Pinmux

I’m not sure I understand the suggestion to use PWM pins.
I’m only looking at the documentation, I don’t have access to a device or software, but I need to determine how I will achieve the physical outputs that I require.
Are you suggesting that I use the PWM peripheral instead of the TSC Controlled Signals or are you saying that the TSC Controlled Signals are routed to the pins with PWM ability?
If the latter, how do I configure them to use TSC Generated Signals, if I select the Special Function value to match the PWM then will the pin mux not expect the associated PWM to be enabled? Or does selecting this SF value with PWM disabled result in the TSC Controlled Signals being routed to these pins.
If this is the case then which pins relate to which TSC Controlled Signal?

Please refer to below topic for TSC and PWM pins control. You can search “TSC” and “PWM” in forum for more topics.

I’m sorry but I don’t understand the relevance in the linked topics to my question.

If I wish to use TSC Controlled Signals as outputs as indicated is possible in the TRM, then which pins can they be routed to?

How do I configure the Pinmux to route TSC Controlled Signals to these pins - do I configure as GPIO or Special Function?

If Configured as GPIO or Special Function above, how does this result in TSC Controlled Signals appearing at the pin rather than the GPIO or SF, Do I configure the pinmux but leave the selected device disabled?

hello steven.lomas,

may I also have more details about your real use-case,
for instance, what’s the functionality you’re going to trigger by using TSC?

The use case is that my company has already designed the hardware which uses the Jetson Orin NX 8GB SoM as the main processing engine. It has other supporting microcontrollers which are connected via a CAN communication channel and may also have some physical GPIO pins interconnected to the Jetson. In addition to cameras, there are other sensors which are either directly connected to the Jetson or via the supporting microcontrollers.

My background is hardware/microcontroller and I’ve almost zero knowledge of Linux, it’s configuration and the Jetson specifics, I’m trying to understand the available options for these signals to propose a solution as to how to communicate between the sensors and the Jetson to produce a coherent synchronised dataset.
I don’t have access to any hardware, this is just a theoretical design challenge at present, primarily from a hardware perspective. My main source of reference is the Technical Reference Manual and the associated datasheets & pinmux spreadsheet downloaded from the Nvidia site.

What I believe we should do is to make use of the GTE to allow us to timestamp any signals generated as sync pulses from the connected sensors and/or supporting microcontrollers to give us a timestamp in the main TSC values and to generate some outgoing physical sync signals on the GPIO pins that are connected to the sensors/supporting micros, ideally also using the common main TSC reference.
I understand that the GTE can only be used on those GPIOs that are on the Sensor Processing Engine or Always On domain and this is true for the inputs to the Jetson for the signals that have been used in our design.
I also need to generate a minimum of 2 outgoing sync pulses from the Jetson that are also inherently sync’d to the Main TSC so as to be in a common time domain as the incoming GTE signals. One of these must be a 1PPS signal as it directly connects to an external sensor that requires this, while the other will connect to one of the supporting micros such that we may want to make this more frequent than 1PPS if possible to reduce any drift between these devices.
From what I read of the TSC Controlled Signals, these would give us exactly the required functionality for these outgoing signals, they would inherently be referenced to the main TSC and allow us to customise the frequency and duration of each of the signals to match our requirements.
This approach to synchronisation is one that we’ve successfully implemented in other designs using other microcontrollers using their equivalent to the TSC Generated Signals features.
Unfortunately we can’t use PWM outputs as the physical pins that are PWM capable have been allocated for other dedicated purposes in our design.

So the questions are:
What pins can be used as outputs from the TSC Controlled Signals as it’s not stated in the TRM and there are no obvious references to TSC Controlled Signals in the pinmux spreadsheet.

How is the pinmux configured to route the TSC Controlled signals to the appropriate pins? I can only see that the Pinmux selects either GPIO or Special Function and the TSC Controlled Signals are not listed in any of the SF options.
Do we have to do something like configure the pin for GPIO and then not enable the GPIO to allow the TSC Controlled Signal or is there some other configuration required?

The TRM also states that of the 4 TSC Controlled Signal outputs, the first is capable of routing to 4 pins while the others can only output to a single pin, but again there is no information relating to which pins or how to configure this, can you expand on this.

No information on the TSC Controlled Signals?

please see-also… Using GPIO pins from Camera Expansion connector pins on AGX Orin - #9 by JerryChang

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