22.4 UART0 Control Registers
22.4.1 SCON0: UART0 Serial Port Control
Bit
7
6
5
4
3
2
1
0
Name
SMODE
Reserved
MCE
REN
TB8
RB8
TI
RI
Access
RW
R
RW
RW
RW
RW
RW
RW
Reset
0
1
0
0
0
0
0
0
SFR Page = 0x0; SFR Address: 0x98 (bit-addressable)
Bit
Name
Reset
Access
Description
7
SMODE
0
RW
Serial Port 0 Operation Mode.
Selects the UART0 Operation Mode.
Value
Name
Description
0
8_BIT
8-bit UART with Variable Baud Rate (Mode 0).
1
9_BIT
9-bit UART with Variable Baud Rate (Mode 1).
6
Reserved
Must write reset value.
5
MCE
0
RW
Multiprocessor Communication Enable.
This bit enables checking of the stop bit or the 9th bit in multi-drop communication buses. The function of this bit is depend-
ent on the UART0 operation mode selected by the SMODE bit. In Mode 0 (8-bits), the peripheral will check that the stop bit
is logic 1. In Mode 1 (9-bits) the peripheral will check for a logic 1 on the 9th bit.
Value
Name
Description
0
MULTI_DISABLED
Ignore level of 9th bit / Stop bit.
1
MULTI_ENABLED
RI is set and an interrupt is generated only when the stop bit is logic 1 (Mode 0)
or when the 9th bit is logic 1 (Mode 1).
4
REN
0
RW
Receive Enable.
Value
Name
Description
0
RECEIVE_DISABLED
UART0 reception disabled.
1
RECEIVE_ENABLED
UART0 reception enabled.
3
TB8
0
RW
Ninth Transmission Bit.
The logic level of this bit will be sent as the ninth transmission bit in 9-bit UART Mode (Mode 1). Unused in 8-bit mode
(Mode 0).
2
RB8
0
RW
Ninth Receive Bit.
RB8 is assigned the value of the STOP bit in Mode 0; it is assigned the value of the 9th data bit in Mode 1.
1
TI
0
RW
Transmit Interrupt Flag.
Set by hardware when a byte of data has been transmitted by UART0 (after the 8th bit in 8-bit UART Mode, or at the begin-
ning of the STOP bit in 9-bit UART Mode). When the UART0 interrupt is enabled, setting this bit causes the CPU to vector
to the UART0 interrupt service routine. This bit must be cleared manually by firmware.
0
RI
0
RW
Receive Interrupt Flag.
Set to 1 by hardware when a byte of data has been received by UART0 (set at the STOP bit sampling time). When the
UART0 interrupt is enabled, setting this bit to 1 causes the CPU to vector to the UART0 interrupt service routine. This bit
must be cleared manually by firmware.
EFM8SB2 Reference Manual
Universal Asynchronous Receiver/Transmitter 0 (UART0)
silabs.com
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