#define SAMD21_SERCOM_CTRLA_IBON 8
#define SAMD21_SERCOM_CTRLA_SAMPR 13
#define SAMD21_SERCOM_CTRLA_TXPO 16
+#define SAMD21_SERCOM_CTRLA_TXPO_TX_0 0
+#define SAMD21_SERCOM_CTRLA_TXPO_TX_2 1
+#define SAMD21_SERCOM_CTRLA_TXPO_TX_0_RTS_2_CTS_3 2
#define SAMD21_SERCOM_CTRLA_RXPO 20
+#define SAMD21_SERCOM_CTRLA_RXPO_RX_0 0
+#define SAMD21_SERCOM_CTRLA_RXPO_RX_1 1
+#define SAMD21_SERCOM_CTRLA_RXPO_RX_2 2
+#define SAMD21_SERCOM_CTRLA_RXPO_RX_3 3
#define SAMD21_SERCOM_CTRLA_SAMPA 22
#define SAMD21_SERCOM_CTRLA_FORM 24
#define SAMD21_SERCOM_CTRLA_CMODE 28