W7500x Reference Manual Version1.1.0
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25.3
Functional description
UART bidirectional communication requires a minimum of two pins: RX, TX
The frame are comprised of:
An Idle Line prior to transmission or reception
A start bit
A data word (8 or 9 bits) least significant bit first
1, 1.5, 2 Stop bits indicating that the frame is complete
The USART interface uses a baud rate generator
A status register (UART1_RISR)
data registers (UART1DR)
A baud rate register (UART1_IBRD,UART1_FBRD)
Figure 45. UART0,1 Block diagram
Figure 46 shows the UART character frame
UART
FIFO status and Interrupt
UARTn Interrupt
Interrupt
Control &
Status
UARTTXINTR
APB interface
Register
Block
32x8
transmit
FIFO
32x12
receive
FIFO
Transmitter
Receiver
UARTRXINTR
UARTMSINTR
UARTRTINTR
UARTEINTR
UARTINTR
nUARTRI
nUARTCTS
nUARTDSR
nUARTDCD
nUARTDTR
nUARTRTS
nUARTOut1
nUARTOut2
UARTRXD
UARTTXD
Baud rate
generator
Read data[11:0]
Write data[7:0]
txd[7:0]
rxd[11:0]
Control and Status
Baud rate divisor
Baud16
Transmit
FIFO
status
Receive
FIFO
status
FIFO flags
UARTCLK
1
0
n
Start
5-8 data bits
LSB
MSB
Parity bit,
if enabled
1-2
Stop bits