The factory test module is a simple module that can be used to test all the I/O pins of the ASIC.
It has three modes of operation:
rst_n
is low).rst_n
is high sel
is low).rst_n
is high and sel
is high).The following table summarizes the modes:
rst_n |
sel |
Mode | uo_out value | uio pins |
---|---|---|---|---|
0 | X | Input mirror | ui_in | High-Z |
1 | 0 | Bidirectional mirror | uio_in | High-Z |
1 | 1 | Counter | counter | counter |
The counter is an 8-bit counter that increments on every clock cycle, and resets when rst_n
is low.
rst_n
low and observe that the input pins (ui_in
) are output on the output pins (uo_out
).rst_n
high and sel
low and observe that the bidirectional pins (uio_in
) are output on the output pins (uo_out
).sel
high and observe that the counter is output on both the output pins (uo_out
) and the bidirectional pins (uio
).# | Input | Output | Bidirectional |
---|---|---|---|
0 | sel / in_a[0] | output[0] / counter[0] | in_b[0] / counter[0] |
1 | in_a[1] | output[1] / counter[1] | in_b[1] / counter[1] |
2 | in_a[2] | output[2] / counter[2] | in_b[2] / counter[2] |
3 | in_a[3] | output[3] / counter[3] | in_b[3] / counter[3] |
4 | in_a[4] | output[4] / counter[4] | in_b[4] / counter[4] |
5 | in_a[5] | output[5] / counter[5] | in_b[5] / counter[5] |
6 | in_a[6] | output[6] / counter[6] | in_b[6] / counter[6] |
7 | in_a[7] | output[7] / counter[7] | in_b[7] / counter[7] |