AT32F421
Series Reference Manual
2022.11.11
Page 8
Rev 2.02
USART frame format and configuration ........................................ 136
DMA transfer introduction ........................................................... 137
Transmission using DMA ............................................................ 137
Reception using DMA ................................................................. 137
Baud rate generation .................................................................. 138
Introduction................................................................................ 138
Configuration ............................................................................. 138
Transmitter ................................................................................ 139
Transmitter introduction .............................................................. 139
Transmitter configuration ............................................................ 139
Receiver ................................................................................... 140
Receiver introduction .................................................................. 140
Receiver configuration ................................................................ 140
Start bit and noise detection ....................................................... 141
Tx/Rx swap ............................................................................... 142
12.10Interrupt requests ...................................................................... 142
12.11I/O pin control............................................................................ 143
12.12USART registers ........................................................................ 143
Status register (USART_STS) .................................................. 144
Data register (USART_DT) ....................................................... 145
Baud rate register (USART_BAUDR) ........................................ 145
Control register1 (USART_CTRL1) ........................................... 145
Control register2 (USART_CTRL2) ........................................... 146
Control register3 (USART_CTRL3) ........................................... 147
Guard time and divider register (USART_GDIV) ........................ 148
Serial peripheral interface (SPI) .................................................. 149
SPI introduction ......................................................................... 149
Functional overview ................................................................... 149
SPI description ........................................................................... 149
Full-duplex/half-duplex selector .................................................. 150
Chip select controller .................................................................. 152
SPI_SCK controller .................................................................... 152
CRC .......................................................................................... 152