Jetson-TX2-Generic-Customer-Pinmux-Template.xlsm Question

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

Hi, NV team,
Based on Jetson-TX2-Generic-Customer-Pinmux-Template.xlsm to create dtsi file.
if we let UART3_TX(H10)
“Customer Usage” set to “unused_UART4_TX”
“Pin direction” set to “Not Assigned”

(1)Then “Req. Initial State” need to be set to “Z” or “N/A” in this excel file?
or just leave this space as blank in excel file?

(2)The created dtsi file will be the same if we set “Req. Initial State” to “Z” or “N/A” ?

(3)If one pin is set to “Customer Usage” = “unused_XXXXXXX”, “Pin direction” = “Not Assigned”.
Then what is the pin real direction? How do we to set this pin to prevent from floating?

Thanks
BR,
Joseph

2

Hi yang,

If set to ‘unused’, the pin direction should be ‘Not Assigned’, and this pin will be in tristate and internal pull down, and just leave ‘Req. Initial State’ as default setting. If set ‘Req. Initial State’ to ‘Z’ then the pin will be in tristate, if set to ‘N/A’ then tristate is disable.

3

Hi, Trumany
Thank for your response.

(1)“If set to ‘unused’, the pin direction should be ‘Not Assigned’, and this pin will be in tristate and internal pull down, and just leave ‘Req. Initial State’ as default setting.”

You mean we can let “Req. Initial State” as empty?

(2)So if we don’t use some pins as NV reference design,
we can set “Customer Usage” = “unused_XXXXXXX”, “Pin direction” = “Not Assigned”?
Or just leave it as original setting?

For example:
If we don’t use I2S1_SDIN(C14) and leave it no-connection in our circuit.
Should we use Setting 1 or Setting 2 in Jetson-TX2-Generic-Customer-Pinmux-Template.xlsm?

Setting 1: “Customer Usage” = “unused_DAP2_DIN”, “Pin direction” = “Not Assigned”
Setting 2:“Customer Usage” = “I2S2_SDATA_IN”, “Pin direction” = “input”

Setting 2 has input pin floating risk, so not suggest to use, right?

BR,
Joseph

4

For (1), yes, just leave it and no change is ok.

For (2), For most unused pins, leave it NC is ok, no need to modify pinmux sheet, you can check the ‘Unused Special Function Interface Pins’ in OEM DG for some pins’ request of unconnected.

5

Hi, Trumany,
We know for most unused pins, leave it NC is ok,
but it also needs correct setting in Jetson-TX2-Generic-Customer-Pinmux-Template.xlsm
to prevent input pin floating, right?

For example:
If we don’t use I2S1_SDIN(C14) and leave it no-connection in our circuit,
if we set :“Customer Usage” = “I2S2_SDATA_IN”, “Pin direction” = “input”
We also need to set “Req. Initial State” as “Int PD” to prevent from floating, right?

BR,
Joseph

6

Generally no such input floating issue will happen. But if you still want to set, then only need to set “Customer Usage” = “unused_XXXXXXX”, “Pin direction” = “Not Assigned”, no other setting needed, and this pin will not be included in pinmux .dtsi file.

7

Thank you, Trumany
Thank for your response and one more question:

In our current HW circuit design,
there is NO any external PU/PD resisters on DP0_HPD/HDMI_CEC/DP1_HPD, and we don’t use these 3 function pins,
and we follow JetsonTX2_OEM_Product_DesignGuide.pdf Table 87. Unused MPIO pins / Pin Groups,
to let these 3 pins unconnected.

What should we set in Jetson-TX2-Generic-Customer-Pinmux-Template.xlsm
to prevent from floating and make false interrupt into CPU?
Please give us suggestion, thanks

[Pinmux default setting]
Signal Name/ Customer Usage / Pin Direction/ Req. Initial State/ Wake Pin
DP0_HPD, DP_AUX_CH0_HPD , Input, , empty, YES
HDMI_CEC, HDMI_CEC , Bidirectional , empty, YES
DP1_HPD, DP_AUX_CH1_HPD , Input , empty, YES

BR,
Joseph

8

You can do as last comment: to set “Customer Usage” = “unused_XXXXXXX”, “Pin direction” = “Not Assigned”,

9

Thank you Trumany