C8051F060_07 SILABS [Silicon Laboratories], C8051F060_07 Datasheet - Page 277

• Manufacturer Part Number: C8051F060_07
• Description: Mixed Signal ISP Flash MCU Family
• Manufacturer: SILABS [Silicon Laboratories]

23.
UART1 is an asynchronous, full duplex serial port offering modes 1 and 3 of the standard 8051 UART.
Enhanced baud rate support allows a wide range of clock sources to generate standard baud rates (details
in
to start reception of a second incoming data byte before software has finished reading the previous data
byte.
UART1 has two associated SFRs: Serial Control Register 1 (SCON1) and Serial Data Buffer 1 (SBUF1).
The single SBUF1 location provides access to both transmit and receive registers. Reading SBUF1
accesses the buffered Receive register; writing SBUF1 accesses the Transmit register.
With UART1 interrupts enabled, an interrupt is generated each time a transmit is completed (TI1 is set in
SCON1), or a data byte has been received (RI1 is set in SCON1). The UART1 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 UART1 interrupt (transmit complete or receive
complete).
Section “23.1. Enhanced Baud Rate Generation” on page
UART1
Rate Generator
UART1 Baud
Write to
SBUF1
Figure 23.1. UART1 Block Diagram
Tx Clock
Rx Clock
Start
Start
Stop Bit
SBUF1
Read
SCON1
TB81
D
SET
CLR
Shift
Input Shift Register
Q
Shift
SFR Bus
(RX Latch)
SBUF1
Rx Control
(9 bits)
Tx Control
0x1FF
SFR Bus
Zero Detector
Rev. 1.2
(TX Shift)
SBUF1
RB81
Load SBUF1
Tx IRQ
Rx IRQ
C8051F060/1/2/3/4/5/6/7
TI1
RI1
SBUF1
Load
Data
Send
278). Received data buffering allows UART1
Interrupt
Serial
Port
RX1
TX1
Crossbar
Crossbar
Port I/O
277