This directory sub-tree contains **serial port loop back tester systems** 
and is organized in

| Directory | Content |
| --------- | ------- |
| [basys3](basys3)   | design for Digilent Basys3 |
| [nexys2](nexys2)   | design for Digilent Nexys2 |
| [nexys3](nexys3)   | design for Digilent Nexys3 |
| [nexys4](nexys4)   | design for Digilent Nexys4 (old CRAM version) |
| [nexys4d](nexys4d) | design for Digilent Nexys A7-100 |
| [s3board](s3board) | design for Digilent S3BOARD |