| .model top | |
| .inputs clk cen ina inb | |
| .outputs outa outb outc outd | |
| .names $false | |
| .names $true | |
| 1 | |
| .names $undef | |
| .subckt DFF clk=clk data=ina out=outa | |
| .param test_param "PARAM_TEST" | |
| .attr test_attr "ATTR_TEST" | |
| .subckt DFF clk=clk data=inb out=outb | |
| .param test_param "PARAM_TEST" | |
| .attr test_attr "ATTR_TEST" | |
| .end |