Electronic – Meaning of certain symbols and labels in Circuit board PCB

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I have a schematic of an electronic circuit board or PCB. I want to know the meaning of certain symbols and labels in the diagram. I have highlighted the diagram below with green, yellow and grey coloured boxes.

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Question 1:
What is the meaning of symbols, >> , < <> > and << ?. See green box.

Question 2:
What is the meaning of n in HDMICLK_DISn? See yellow box.

Question 3:
What is the meaning of 6, 10, 11 in grey box?

Question 4: Why the resistors have values as zero at certain places? What does it signify? For example see the 2 resistors on top of the schematic. They have value 0.

I would appreciate answer(s) to any/some/all of above questions.

Best Answer

>> , < <> > and <<: These are called "off-page connectors". >> means that the signal originates from this page (it's an output from this page) and goes to another page. The numbers "6,10,11" are the pages that this signal goes to. On those pages you'll find those signals next to the << symbol. This symbol means that that signal originates from a different page and enters this page (its an input to this page). <<>> means this signal is a bidirectional signal. The signal can originate from this page or the other page it is present on.

The n in HDMICLK_DISn typically denotes an active low signal. I dont know about HDMI's specs but from the signal name I assume it has a clock (CLK = clock). Some name + _dis (HDMICLK_DIS) typically means that this signal's purpose to to disable some function, in this case the clock signal for HDMI, make this signal high and the clock will be disabled. Now add the "n" to then end (HDMICLK_DISn) and again it's an active low signal. A high signal on this line will keep the HDMICLK enabled but now a low signal (typically GND) will disable the HDMICLK