MS51
Nov. 28, 2019
Page
374
of 491
Rev 1.00
MS51
32K
SE
RIES
TE
CHNICAL RE
F
EREN
CE MA
N
UAL
SCON_1
– Serial Port 1 Control
Register
SFR Address
Reset Value
SCON_1
F8H, All pages, Bit addressable
0000_0000 b
7
6
5
4
3
2
1
0
SM0_1/FE_1
SM1_1
SM2_1
REN_1
TB8_1
RB8_1
TI_1
RI_1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Bit
Name
Description
7
SM0_1/FE_1
Serial port 1 mode select
SMOD0_1 (T3CON.6) = 0:
See Table 6.9-2 Serial Port UART1 Mode / baudrate Description for details.
SMOD0_1 (T3CON.6) = 1:
SM0_1/FE_1 bit is used as frame error (FE) status flag. It is cleared by software.
0 = Frame error (FE) did not occur.
1 = Frame error (FE) occurred and detected.
6
SM1_1
5
SM2_1
Multiprocessor communication mode enable
The function of this bit is dependent on the serial port 1 mode.
Mode 0:
No effect.
Mode 1:
This bit checks valid stop bit.
0 = Reception is always valid no matter the logic level of stop bit.
1 = Reception is valid only when the received stop bit is logic 1 and
the received
data matches “Given” or “Broadcast” address.
Mode 2 or 3:
For multiprocessor communication.
0 = Reception is always valid no matter the logic level of the 9
th
bit.
1 = Reception is valid only when the received 9th bit is logic 1 and
the received
data matches “Given” or “Broadcast” address.
4
REN_1
Receiving enable
0 = Serial port 1 reception Disabled.
1 = Serial port 1 reception Enabled in Mode 1,2, or 3. In Mode 0, reception is initiated by the
condition REN_1 = 1 and RI_1 = 0.
3
TB8_1
9
th
transmitted bit
This bit defines the state of the 9
th
transmission bit in serial port 1 Mode 2 or 3. It is not used in
Mode 0 or 1.
2
RB8_1
9
th
received bit
The bit identifies the logic level of the 9
th
received bit in serial port 1 Mode 2 or 3. In Mode 1,
RB8_1 is the logic level of the received stop bit. SM2_1 bit as logic 1 has restriction for
exception. RB8_1 is not used in Mode 0.