gc80c520a CORERIVER Semiconductor, gc80c520a Datasheet - Page 167

• Manufacturer Part Number: gc80c520a
• Description: Midas1.0 Family Mask Rom/eprom/romless 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

15.15 Serial Port Control Register (SCON)
Bit No.
SM0, SM1
98h
Symbol
SM2
REN
TB8
RB8
RI
TI
MiDAS1.0 Family
R/W(0)
SM0
7
Function
Serial Port Mode. These bits control the mode of serial port.
SM0
0
0
1
1
Automatic Address Recognition. The function of this bit is dependent on the serial port
mode.
Mode 1: When set, reception is ignored if invalid stop bit received.
Mode 2/3: When this bit is set, automatic address recognition is enabled in modes 2 and
3. This will prevent the RI bit from being set, and an interrupt being asserted, if the 9
bit received is not 1.
Receive Enable. This bit enables/disables the serial port receiver shift register.
0: serial port reception disabled.
1: serial port receiver enabled (modes 1, 2 and 3). Initiate synchronous reception (mode
0).
9
port modes 2 and 3.
9
data in serial port modes 2 and 3. In serial port mode 1, when SM2=0, RB8 is the state
of the stop bit. RB8 is not used in mode 0.
Transmitter Interrupt Flag. This bit indicates that data in the serial port buffer has been
completely shifted out. In serial port mode 0, TI is set at the end of the 8
all other modes, this bit is set at the end of the last data bit. This bit must be manually
cleared by software.
Receiver Interrupt Flag. This bit indicates that a byte of data has been received in the
serial port buffer. In serial port mode 0, RI is set at the end of the 8
mode 1, RI is set after the last sample of the incoming stop bit subject to the state of
th
th
Transmission Bit State. This bit defines the state of the 9
Received Bit State. This bit identifies the state of the 9
R/W(0)
SM1
6
SM1
0
1
0
1
R/W(0)
SM2
5
Mode
0
1
2
3
R/W(0)
Page 167 of 187
REN
4
Period
8-bit shift register (OSC/4)
8-bit UART (Variable)
9-bit UART (OSC/32 or OSC/16)
9-bit UART (Variable)
R/W(0)
TB8
3
R/W(0)
RB8
2
R/W(0)
th
th
TI
1
reception bit of received
transmission bit in serial
th
R/W(0)
bit. In serial port
RI
0
th
data bit. In
SCON
th