Mitsubishi Motors DS5000TK User Manual
Page 35
USER’S GUIDE
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35
SERIAL CONTROL REGISTER
Label:SCON
Register Address: 098H
D7
D6
D5
D4
D3
D2
D1
D0
SM0
SM1
SM2
REN
TB8
RB8
TI
RI
Bit Description:
SCON.7, SCON.6:
SM0, SM1
“Mode Select”:
Used to select the operational mode of the serial I/O port as follows:
SM0
SM1
MODE
WORD FUNCTION
BAUD LENGTH
CLOCK PERIOD
0
0
Mode 0
SYNC
8–bits
12 t
CLK
0
1
Mode 1
ASYNC
10–bits
Timer 1 Overflow
1
0
Mode 2
ASYNC
11–bits
64 t
CLK
or 32 t
CLK
1
1
Mode 3
ASYNC
11–bits
Timer 1 Overflow
Initialization:
Cleared to 0 on any type of reset.
SCON.5:
SM2
“Multiple MCU Comm”:
Used to enable the multiple microcontroller communications feature for
modes 2 and 3. When SM2=1, RI will be activated only when serial words
are received which cause RB8 to be set to a 1.
Initialization:
Cleared to a 0 on any type of reset.
SCON.4:
REN
“Receive Enable”:
When set to 1, the receive shift register will be enabled. Disabled when
cleared to 0.
Initialization:
Cleared to a 0 on any type of reset.
SCON.3:
TB8
“Xmit Bit 8”:
Can be set or cleared to define the state of the 9th data bit in modes 2 and 3 of
a serial data word.
Initialization:
Cleared to a 0 on any type of reset.
SCON.2:
RB8
“Rec. Bit 8”:
Indicates the state of the 9th data bit received while in modes, 2 or 3. If mode
1 is selected with SM2=0, RB8 is the state of the stop bit which was received.
RB8 is not used in mode 0.
Initialization:
Cleared to a 0 on any type of reset.
SCON.1:
TI
“Xmit Interrupt”:
Status bit used to signal that a data word has been completely shifted out. In
mode 0, it is set at the end of the 8th data bit. Set when the stop bit is trans-
mitted in all other modes.