80C186EC/80C188EC Microprocessor User's Manual

SERIAL COMMUNICATIONS UNIT
Register Name:
Register Mnemonic:
Register Function:
Serial Port Control Register
SxCON
Controls serial port operating modes.
15 0
S
B
R
K
T
B
8
C
E
N
R
E
N
E
V
N
P
E
N
M
2
M
1
M
0
A1277-0A
Bit
Mnemonic
Bit Name
Reset
State
Function
SBRK Send Break 0 Setting SBRK drives TXD low. TXD remains low
until SBRK is cleared.
TB8
CEN
REN
EVN
PEN
Transmitted
Bit 8
Clear-to-
Send Enable
Receive
Enable
Even Parity
Select
Parity
Enable
0 TB8 is the eighth data bit transmitted in modes 2
and 3.
0 When CEN is set, no transmissions will occur until
the CTS pin is asserted.
0 Set to enable the receive machine.
0 When parity is enabled, EVN selects between even
and odd parity. Set for even, clear for odd parity.
0 Setting PEN enables the parity generation/checking
for all transmissions/receptions.
M2:0 Serial Port
Mode Field
0 Operating mode for the serial port channel.
M2 M1 M0 Mode
0 0 0 Synchronous Mode0
0 0 1 10-Bit Asynch Mode1
0 1 0 11-Bit Asynch Mode2
0 1 1 11-Bit Asynch Mode3
1 0 0 9-Bit Asynch Mode4
1 0 1 Reserved
1 1 0 Reserved
1 1 1 Reserved
NOTE:
Reserved register bits are shown with gray shading. Reserved bits must be written to
a logic zero to ensure compatibility with future Intel products.
Figure 11-13. Serial Port Control Register (SxCON)
11-15