Automatic Configuration

XJDeveloper can create some PCOLA/SOQ data automatically, based on device categorisations and knowledge of the circuit. Automatically configured device groups have the text [generated] appended to their name to make them easily identifiable.

Generated device group weights

Automatically generated device groups are created from the category to which devices are assigned on the Categorise Devices screen.

In the case of Passive devices, names of assigned library files may be used to suggest if the device in question is likely to be agnostic to its orientation – for instance, a resistor.

N.B. Due to how XJDeveloper scores passive devices, it is not possible to calculate a score for a device with a user-defined Passive Device File. In these cases, it is advisable to create a group for these devices, and score them manually.

Each generated device group will have a default set of property weights assigned, as shown below.

	Presence	Correctness	Orientation	Live	Alignment	Shorts	Opens	Quality
Orientation relevant	0.30	0.20	0.20	0.20	0.10	0.40	0.40	0.20
Orientation irrelevant	0.35	0.25	0.00	0.25	0.15	0.40	0.40	0.20

Generated device scores

The scores for a given device depend on the categorisation of that device. The following table outlines the automatically generated scores for each type of device, with further details below.

Score overview

	Presence	Correctness	Orientation	Live	Alignment
JTAG Devices	Full	Full	Full	Partial Full	None
Logic Devices	Full	Full	Full	Full	None
Test Devices	All scores read from assigned Device file
Buffers on TAP nets	Full	Full	Full	Full	None
Series resistors on TAP nets	Full	Partial	N/A	Full	None
Series resistors between JTAG pins	Full	Partial	N/A	Full	None
Pull resistors on JTAG nets	Partial Full	Partial	N/A	Partial Full	None
Series resistors between JTAG and Test devices	Full	Partial	N/A	Full	None
Other resistors	None	None	N/A	None	None
Capacitors	None	None	None	None	None

Further device details

JTAG Devices

A JTAG device's Live score may vary, receiving Full if the device has only one power pin, and Partial otherwise. This is due to the possibility that only the boundary scan function of the device is powered

Logic Devices

These will only be assigned the displayed score if they are included as part of the Connection Test, or else can either drive or be driven by a test device.

Test Devices

Scores for Test Devices are obtained from the file assigned to each device. See PCOLA scores in Test Device files for further details.

Pull resistors on JTAG nets

In the case where the JTAG devices on the net pulled by such a resistor do not have internal pulls enabled, these will get Full coverage for their Presence and Live properties. Otherwise, only Partial cover may be awarded.

Alignment for all devices

Due to the limitations of Boundary Scan technology, XJTAG cannot determine anything about the alignment of a device, so this property will always score None.

Generated connection scores

Each connection to a device is scored according to the test coverage for shorts, opens and stuck high or low.

Connection scores are determined as follows:

Shorts

• Full if Shorts cover is present.
• Partial if either of Stuck High or Stuck Low is covered.
• None if none of the above conditions are met.

Opens

• Full if Opens cover is present.
• None if Opens cover is not present.

Quality

• None similar to the Alignment property of devices, limitations of Boundary Scan mean that XJTAG cannot tell anything about the solder quality of a connection.

Score priorities

There are three sources that a proeprty score may come from. These are listed below in descending priority order:

1. Manually overridden property score
2. XJDeveloper generated property score
3. For devices: the default score from the parent device group

A higher priority score will completely override anything at a lower priority.