ST72T311 ST Microelectronics, ST72T311 Datasheet - Page 61

• Manufacturer Part Number: ST72T311
• Description: 8-BIT MCU WITH 8 TO 16K OTP/EPROM
• Manufacturer: ST Microelectronics

SERIAL COMMUNICATIONS INTERFACE (Cont’d)
CONTROL REGISTER 1 (CR1)
Read/Write
Reset Value: Undefined
Bit 7 = R8 Receive data bit 8.
This bit is used to store the 9th bit of the received
word when M=1.
Bit 6 = T8 Transmit data bit 8.
This bit is used to store the 9th bit of the transmit-
ted word when M=1.
Bit 4 = M Word length.
This bit determines the word length. It is set or
cleared by software.
0: 1 Start bit, 8 Data bits, 1 Stop bit
1: 1 Start bit, 9 Data bits, 1 Stop bit
Bit 3 = WAKE Wake-Up method.
This bit determines the SCI Wake-Up method, it is
set or cleared by software.
0: Idle Line
1: Address Mark
CONTROL REGISTER 2 (CR2)
Read/Write
Reset Value: 0000 0000 (00h)
Bit 7 = TIE Transmitter interrupt enable .
This bit is set and cleared by software.
0: interrupt is inhibited
1: An SCI interrupt is generated whenever
Bit 6 = TCIE Transmission complete interrupt ena-
ble
This bit is set and cleared by software.
0: interrupt is inhibited
TIE
R8
TDRE=1 in the SR register.
7
7
TCIE
T8
RIE
-
ILIE
M
WAK E
TE
RE
-
RWU
-
SBK
0
0
-
1: An SCI interrupt is generated whenever TC=1 in
Bit 5 = RIE Receiver interrupt enable .
This bit is set and cleared by software.
0: interrupt is inhibited
1: An SCI interrupt is generated whenever OR=1
Bit 4 = ILIE Idle line interrupt enable.
This bit is set and cleared by software.
0: interrupt is inhibited
1: An SCI interrupt is generated whenever IDLE=1
Bit 3 = TE Transmitter enable.
This bit enables the transmitter and assigns the
TDO pin to the alternate function. It is set and
cleared by software.
0: Transmitter is disabled, the TDO pin is back to
1: Transmitter is enabled
Note: during transmission, a “0” pulse on the TE
bit (“0” followed by “1”) sends a preamble after the
current word.
Bit 2 = RE Receiver enable.
This bit enables the receiver. It is set and cleared
by software.
0: Receiver is disabled, it resets the RDRF, IDLE,
1: Receiver is enabled and begins searching for a
Bit 1 = RWU Receiver wake-up.
This bit determines if the SCI is in mute mode or
not. It is set and cleared by software and can be
cleared by hardware when a wake-up sequence is
recognized.
0: Receiver in active mode
1: Receiver in mute mode
Bit 0 = SBK Send break.
This bit set is used to send break characters. It is
set and cleared by software.
0: No break character is transmitted
1: Break characters are transmitted
Note: If the SBK bit is set to “1” and then to “0”, the
transmitter will send a BREAK word at the end of
the current word.
the SR register
or RDRF=1 in the SR register
in the SR register.
the I/O port configuration.
OR, NF and FE bits of the SR register.
start bit.
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