This attribute specifies the initial VPI of the optional Programmable
VCC Space.
If numNonZeroVpisForVccs is 0 then the Programmable VCC
Space does not exist and the value of this attribute is ignored. If
numNonZeroVpisForVccs is greater than 0 the Programmable VCC
Space exists and covers the VPI values ranging from
firstNonZeroVpiForVccs to (firstNonZeroVpiForVccs +
numNonZeroVpisForVccs - 1).
The initial VPI of the Programmable VCC Space must either be 1
or a non-zero multiple of 16.
The values of all attributes provisioned in this group must adhere to
the guidelines laid down in the description of the Provisioned
group.