This demonstration board includes 24 full-BS interconnects,
two of which (nets 10 and 11 in figure 5.1) share their BS cells between
the two BS chains. The information required for test program generation is
once more obtainable from the SN74BCT8244 data sheet and from the board
structural information (netlist), and comprises the following fields for
each interconnect:
- Number and identification of the BS chains that have cells present
in this interconnect
Concerning the output pins present:
- Number of output pins and (for each one) location, in the BS chain,
of the output cell, the control cell (if any) and the logic value that
drives the pin to the high-impedance state.
Concerning the input pins present:
- Number of input pins and (for each one) location, in the BS chain,
of the input cell.
Concerning the bidirectional pins present:
- Number of bidirectional pins and (for each one) location, in the BS
chain, of the output cell, the input cell, the control cell and the
logic value that drives the pin to the high-impedance state.
Concerning the primary input pins present (it is assumed that each
primary input pin is driven by an external test channel that enables the
primary input to be set to the high-impedance state):
- Number of primary input pins and (for each one) an identification
number and the control value that drives the respective test channel
to the high-impedance state.
Concerning the primary output pins present:
- Number of primary output pins and (for each one) an identification
number.
Finally, and considering the possible case of interconnects that tie
unused input pins to ground or VCC:
- Is the interconnect at a fixed logic level and if so at which logic
value?
The information required for generating the test program segment
concerning the full-BS interconnects, in our demonstration board, is
presented in table 1.
Net
ident. |
#
BS chains |
BS
chain ident. |
#
of output pins |
Output
cell |
Control
cell |
High
imped. |
#
of input pins |
Input
cell |
#
of bidir. pins |
#
of prim. inputs |
Prim.
input |
High
imped. |
#
of prim. outputs |
Prim.
output |
Fixed
level? |
Logic
level |
Net 0 |
1 |
0 |
0 |
- |
- |
- |
1 |
2 |
0 |
1 |
0 |
0 |
0 |
- |
No |
- |
Net 1 |
1 |
0 |
0 |
- |
- |
. |
1 |
3 |
0 |
1 |
1 |
0 |
0 |
- |
No |
- |
Net 2 |
1 |
0 |
0 |
- |
- |
. |
1 |
4 |
0 |
1 |
2 |
0 |
0 |
- |
No |
- |
Net 3 |
1 |
0 |
0 |
- |
- |
. |
1 |
5 |
0 |
1 |
3 |
0 |
0 |
- |
No |
- |
Net 4 |
1 |
0 |
0 |
- |
- |
. |
1 |
6 |
0 |
1 |
4 |
0 |
0 |
- |
No |
- |
Net 5 |
1 |
0 |
0 |
- |
- |
. |
1 |
7 |
0 |
1 |
5 |
0 |
0 |
- |
No |
- |
Net 6 |
1 |
0 |
0 |
- |
- |
. |
1 |
8 |
0 |
1 |
6 |
0 |
0 |
- |
No |
- |
Net 7 |
1 |
0 |
0 |
- |
- |
. |
1 |
9 |
0 |
1 |
7 |
0 |
0 |
- |
No |
- |
Net 8 |
1 |
0 |
0 |
- |
- |
. |
1 |
0 |
0 |
0 |
- |
- |
0 |
- |
Yes |
0 |
Net 9 |
1 |
0 |
0 |
- |
- |
. |
1 |
1 |
0 |
0 |
- |
- |
0 |
- |
Yes |
0 |
Net 10 |
2 |
0 |
1 |
16 |
1 |
1 |
0 |
- |
0 |
0 |
- |
- |
0 |
- |
No |
- |
|
|
1 |
0 |
- |
- |
- |
1 |
8 |
0 |
|
|
|
|
|
|
|
Net 11 |
2 |
0 |
1 |
17 |
1 |
1 |
0 |
- |
0 |
0 |
- |
- |
0 |
- |
No |
- |
|
|
1 |
0 |
- |
- |
- |
1 |
9 |
0 |
|
|
|
|
|
|
|
Net 12 |
1 |
0 |
0 |
- |
- |
- |
1 |
18 |
0 |
0 |
- |
- |
0 |
- |
Yes |
0 |
Net 13 |
1 |
0 |
0 |
- |
- |
- |
1 |
19 |
0 |
0 |
- |
- |
0 |
- |
Yes |
0 |
Net 14 |
1 |
1 |
1 |
- |
- |
- |
1 |
0 |
0 |
0 |
- |
- |
0 |
- |
Yes |
0 |
Net 15 |
1 |
1 |
1 |
- |
- |
- |
1 |
1 |
0 |
0 |
- |
- |
0 |
- |
Yes |
0 |
Net 16 |
1 |
1 |
1 |
10 |
0 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
0 |
No |
- |
Net 17 |
1 |
1 |
1 |
11 |
0 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
1 |
No |
- |
Net 18 |
1 |
1 |
1 |
12 |
0 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
2 |
No |
- |
Net 19 |
1 |
1 |
1 |
13 |
0 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
3 |
No |
- |
Net 20 |
1 |
1 |
1 |
14 |
1 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
4 |
No |
- |
Net 21 |
1 |
1 |
1 |
15 |
1 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
5 |
No |
- |
Net 22 |
1 |
1 |
1 |
16 |
1 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
6 |
No |
- |
Net 23 |
1 |
1 |
1 |
17 |
1 |
1 |
0 |
- |
0 |
0 |
- |
- |
1 |
7 |
No |
- |
Table 1: Information required to generate
the test program for full-BS interconnects. |