What are “passive” pins?

Hi All,

I would like to ask one question on DM6437 pins.

What are “passive” pins in DM6437?

Although the DM6437 manual TMS320DM6437 Digital Media Processor (SPRS345d) did not describe pins as being passive or not, I found this characterization in the schematics for Spectrum EVM6437. Shown in the following screenshot, many pins of

1.      Vss

2.      DVdd33

3.      DVDDR2

pins are all classified as “passive”, and there are a total of eight types in the drop down.

I was curious why those three types listed above, commonly regarded as power/ground pins, are classified as “passive”, so I went to the list of all “power” type pins to get a comparison. Curiously, I also found pins of

1.      Vss

2.      DVdd33

3.      DVDDR2

in that class.

What indeed are passive pins? I only know that several elementary electrical components, including resistance, capacitor and inductor, are called “passive” because they cannot control current of other components. Is that “passive” the same concept as the “passive” of pins here?

It is also interesting to see in the first screenshot, that at least three distinct types of pins are classified as “passive” type:

1.      I/O/Z

2.      GND

3.      SUPPLY

So does this mean from here we can infer that being “passive” or not and being either of {input, output, supply, ground} are not of the same dimension, which can be expressed in the following matrix form:

?

I am really confused with this “passive” type. Could anyone explain this for me?

Thanks,

Zheng