C8051F326-TB Silicon Laboratories Inc, C8051F326-TB Datasheet - Page 117

• Manufacturer Part Number: C8051F326-TB
• Description: BOARD PROTOTYPING W/C8051F326
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F326-TB

• Contents: Board
• Processor To Be Evaluated: C8051F326/F327
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F326
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

13. UART0
UART0 is an asynchronous, full duplex serial port offering a variety of data formatting options. A dedicated
baud rate generator with a 16-bit timer and selectable prescaler is included, which can generate a wide
range of baud rates (details in Section “13.1. Baud Rate Generator” on page 118). A received data FIFO
allows UART0 to receive up to three data bytes before data is lost and an overflow occurs.
UART0 has six associated SFRs. Three are used for the Baud Rate Generator (SBCON0, SBRLH0, and
SBRLL0), two are used for data formatting, control, and status functions (SCON0, SMOD0), and one is
used to send and receive data (SBUF0). The single SBUF0 location provides access to both transmit and
receive registers. Writes to SBUF0 always access the Transmit register. Reads of SBUF0 always
access the buffered Receive register; it is not possible to read data from the Transmit register.
With UART0 interrupts enabled, an interrupt is generated each time a transmit is completed (TI0 is set in
SCON0), or a data byte has been received (RI0 is set in SCON0). The UART0 interrupt flags are not
cleared by hardware when the CPU vectors to the interrupt service routine. They must be cleared manually
by software, allowing software to determine the cause of the UART0 interrupt (transmit complete or receive
complete). If additional bytes are available in the Receive FIFO, the RI0 bit cannot be cleared by software.
SYSCLK
USBCLK
SBRLH0
Timer (16-bit)
Baud Rate Generator
SBRLL0
EN
Figure 13.1. UART0 Block Diagram
SBCON0
Overflow
(1, 4, 12, 48)
Pre-Scaler
Rev. 1.1
Control / Status
Data Formatting
Interrupt
UART0
SMOD0
SCON0
C8051F326/7
RX FIFO
(3 Deep)
SBUF0
Logic
Logic
RX
TX
Write to SBUF0
Read of SBUF0
TX0
RX0
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