11.2 XCK Pin Configuration

As the table Table 11-1 shows, when UMSEL[1:0] bits are set to "01", the USART will operate in master or slave synchronous mode; when UMSEL[1:0] bits are set to "11", the USART will operate at master SPI mode. When the USART operates at master synchronous or SPI mode, users need configure the XCK pin output direction; when the USART operates at slave synchronous mode, users need configure the XCK pin input direction.

Figure 11-2. USART Control and Status Register n C

Bits 7:6 – UMSEL[1:0]: USART Mode Select as shown in the table below.

Table 11-1. USART Mode Selection
UMSEL[1:0]Mode
00Asynchronous USART
01Synchronous USART
10Reserved
11Master SPI (MSPIM)