Texas Instruments MSC1210 - Manual (Page 318)

Bit Addressable SFRs (alphabetical)
F-8
Serial Control (SCON)
SFR Name: SCON
SFR Address: 98
H
Bit−Addressable: Yes
Bit−Definitions:
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
Name SM0 SM1 SM2 REN TB8 RB8 TI RI
Bit Address 9FH 9EH 9DH 9CH 9BH 9AH 99H 98H
SM0/SM1– Serial Mode. These two bits, taken together, select the serial
mode in which the serial port will operate.
SM0 SM1 Serial Mode Description Baud
0 0 0 Shift Register Oscillator/12
0 1 1 8-Bit UART Variable (T1 or T2)
1 0 2 9-Bit UART Oscillator/64 or /32
1 1 3 9-Bit UART Variable (T1 or T2)
SM2—Serial Mode 2 (Multiprocessor Communication). When this bit is set,
multiprocessor communication is enabled in modes 2 and 3 causing the RI bit
to only be set when the ninth bit of a byte received is set. In mode 1, RI is only
set if a valid stop bit is received. SM2 must be cleared in mode 0.
REN—Received Enable. This bit must be set to enable data reception via the
serial port. No data will be received by the serial port if this bit is clear.
TB8—Transmit Bit 8. When in modes 2 and 3, this is the ninth bit sent when
a byte is written to SBUF.
RB8—Receive Bit 8. When in modes 2 and 3, this is the ninth bit that was re-
ceived. In mode 1, and if SM2 is set, RB8 holds the value of the stop bit that
was received. RB8 is not used in mode 0.
TI—Transmit Interrupt. Set by hardware when the byte previously written to
SBUF has been completely clocked out the serial port.
RI—Receive Interrupt. Set by hardware when a byte has been received by
the serial port and is available to be read in SBUF.