System pins and DUT pins are two main types of pins.

  • System Pins—Use for static control of system-level circuits. These pins have limited functionality and cannot be used during pattern bursts.
  • DUT Pins —Use for one channel mapping (from the DUT pin to an instrument channel) per site. Each instrument channel can be associated with a single site or shared across multiple sites. Sharing across multiple sites could look like a shared circuit on a load board that interfaces to multiple sites. If multiple sites have the same channel mapping for the same pin, this is referred to as a shared pin.
    • In the following example, PinA is mapped to channel 0 for both sites 0 and 1, and mapped to channel 1 for sites 2 and 3. 
    <Connections>
<Connection pin="PinA" siteNumber="0,1" instrument="Dig" channel="0" />
<Connection pin="PinA" siteNumber="2,3" instrument="Dig" channel="1" />
 </Connections>

    Any configuration of a shared pin is applied to all sites that are mapped to the same channel. In the previous example pin map, configuring VOL for site0/PinA applies the value to both site0/PinA and site1/PinA. When configuring a shared pin, you need to configure only one of the sites that is mapped to the shared channel. If you do not specify a site when configuring a shared pin, the value applies to all sites for the pin, regardless of the channel, just as it is with any other DUT pin.

    Measurements taken on shared pins are returned per site, just as they are for any other DUT pin. In the previous example pin map, taking a PPMU measurement on PinA returns four results, one for each site. The results are identical for all the sites that are mapped to the same channel. For example, a single value is returned for measurements taken on site0/PinA or site1/PinA.

    Considerations When Using Shared Pins

    When bursting a pattern that contains a shared pin, the physical channel that is mapped to the shared pin is active in the burst if at least one site of the shared pin is enabled and included in the burst. In the previous example pin map, bursting a pattern that contains PinA on either site0 or site1 causes channel 0 to be active in the burst.

    The burst results for a shared pin are included in all sites that the shared pin is mapped to. Capture waveform data and History RAM results for shared pins are present in the samples for all sites the pin is shared on.

    A failure on a shared pin is reported on all sites of the shared pin. In the previous example pin map, a failure on site0/PinA or site1/PinA causes both sites to report the failure.

    When using shared pins in a source memory site unique waveform, the waveform must send the same data for all sites that have the same channel mapping.

    When working with shared pins, call the Get Pin Results Pin Information API with pin lists instead of channel lists. NI-Digital Pattern Driver returns an error if the Get Pin Results Pin Information API is called with a channel that is shared on multiple sites.