目前CC2540 USART0 uart用的是P0_2,P0_3已经调通，USART1串口要用的是P1_6,P1_7，我调了很久没调通，请问该怎么配置呢 ？相关寄存器该如何配置？
下面的宏该怎么看呢
#if (HAL_UART_ISR == 1) //串口的模式是什么样的呢
#define HAL_UART_PERCFG_BIT 0x01 // USART0 on P0, Alt-1; so clear this bit.
#define HAL_UART_Px_RX_TX 0x0C // Peripheral I/O Select for Rx/Tx.
#define HAL_UART_Px_RX 0x04 // Peripheral I/O Select for Rx.
#define HAL_UART_Px_RTS 0x20 // Peripheral I/O Select for RTS.
#define HAL_UART_Px_CTS 0x10 // Peripheral I/O Select for CTS.
#else
#define HAL_UART_PERCFG_BIT 0x02 // USART1 on P1, Alt-2; so set this bit.//Alt-1、Alt-2是什么意思呢
#define HAL_UART_Px_RTS 0x20 // Peripheral I/O Select for RTS.
#define HAL_UART_Px_CTS 0x10 // Peripheral I/O Select for CTS.
#define HAL_UART_Px_RX_TX 0xC0 // Peripheral I/O Select for Rx/Tx.
#define HAL_UART_Px_RX 0x80 // Peripheral I/O Select for Rx.
#endif
