# BPI  Open debugger burn board Abbreviations

| CSn    | Chip Select (active low)         |
| ------ | -------------------------------- |
| DC     | Debug Clock                      |
| DD     | Debug Data                       |
| RST    | Debug Reset                      |
| DUT    | Device Under Test                |
| GND    | Ground                           |
| LED    | Light Emitting Diode             |
| MISO   | Master In Slave Out              |
| MOSI   | Master Out Slave In              |
| RF     | Radio Frequency                  |
| SCLK   | Serial Clock                     |
| SoC    | System-on-Chip                   |
| SPI    | Serial Peripheral Interface      |
| USB    | Universal Serial Bus             |
| Target | Positive voltage on target       |
| CLK    | SWD Clock                        |
| DIO    | SWD DATA Input/Output            |
| TMS    | JTAG Test Mode Select            |
| TCK    | JTAG Test Clock Input            |
| TDO    | JTAG Test Data Output            |
| TDI    | JTAG Test Data Input             |
| SRST   | JTAGTest Reset Input, Active Low |
| RXD    | USB Serial Input                 |
| TXD    | USB Serial Output                |