|The test protocol for full-BS interconnects
and non-BS clusters, described in the previous chapter, made it clear that
testing interconnects or clusters associated with cells from different BS
chains, or with primary I/O pins of the PCB, require a co-ordinated
procedure to complete test vector application from all driving pins,
before the responses start to be captured. A synchronisation protocol is
required when co-ordinating the BS infrastructure and the external test
resources, which may be implemented by a simple handshake procedure for
test vector application and response capturing on both sides, based on a
sync output and a sync input and leading to the following basic test
The BS test controller will set the sync output to notify
the external test equipment that the application of the test vector
through the BS infrastructure is finalised and will reset it to notify
that all test responses were captured through the BS infrastructure.
- Set the sync output to a pre-defined logic value
(0 or 1).
Following the application of each test vector through the
BS infrastructure and its notification through the sync output, the BS
test controller will wait for notification from the external test
equipment (that the external test stimuli were applied as well) before
capturing any responses. Similarly, after concluding the response
capturing phase, the BS test controller will wait for notification from
the external test equipment (that response capturing was finalised there
as well), before initiating the application of the next test vector.
- Wait until the sync input is set to a pre-defined
logic value (0 or 1).