SPRUJF1C November 2024 – December 2025 AM2612
The AM261x LaunchPad uses the XDS110 as a USB2.0 to UART bridge for terminal access. UART0 transmit and receive signals of the AM261x SoC are mapped to the XDS110 with a dual channel isolation buffer (ISO7721DR) for translating from the 3.3V IO voltage supply to the 3.3V XDS supply. The XDS110 is connected to a micro-B USB connector for the USB 2.0 signals. ESD protection is provided to the USB 2.0 signals by a transient voltage suppression device (TPD4E02B04DQAR). The micro-B USB connector's VBUS 5V power is mapped to a low dropout regulator (TPS79601DRBR) to generate the 3.3V XDS110 supply. A separate 3.3V supply for the XDS110 allows for the emulator to maintain a connection when power to the LaunchPad is removed.
Two instances of UART3 are brought out to the BoosterPack headers. If the pinmux on AM261x pins C19 and C18 are configured for UART3 TXD/RXD, the signals can be accessed on header J1. If the pinmux on AM261x pins A14 and B14 are configured for UART, the signals can be accessed on header J5. Multiplexers are included on the paths from the AM261x MCU to the BoosterPack headers to enable other BoosterPack modes. The logic tables for these muxes are shown below:
| BP_MUX_SW_S4 | BP_BO_MUX_EN_N | Mux Output (1A) |
|---|---|---|
| 0 | 0 | Hi-Z |
| 0 | 1 | UART3_RXD |
| 1 | 0 | Hi-Z |
| 1 | 1 | SDFM1_D0 |
| BP_MUX_SW_S5 | COM |
|---|---|
| 0 | UART3_TXD |
| 1 | PR1_PRU1_GPIO3 |
| BP_MUX_SW_S1 | COM |
|---|---|
| 0 | UART3_RXD |
| 1 | PR1_PRU0_GPIO19 |
Figure 2-22 LP-AM261 UART Interface