T89C51CC01 Atmel, T89C51CC01 Datasheet - Page 58

• Manufacturer Part Number: T89C51CC01
• Description: Enhanced 8-Bit Microcontroller
• Manufacturer: Atmel

Registers
58
T89C51CC01
For slaves A and B, bit 2 is a don’t care bit; for slave C, bit 2 is set. To communicate with
all of the slaves, the master must send an address FFh. To communicate with slaves A
and B, but not slave C, the master can send and address FBh.
Table 35. SCON Register
SCON (S:98h)
Serial Control Register
Reset Value = 0000 0000b
Bit addressable
Number
FE/SM0
Bit
7
7
6
5
4
3
2
1
0
Mnemonic Description
SM1
SM0
SM1
SM2
REN
RB8
Bit
TB8
FE
RI
6
TI
Framing Error bit (SMOD0=1)
Clear to reset the error state, not cleared by a valid stop bit.
Set by hardware when an invalid stop bit is detected.
Serial port Mode bit 0 (SMOD0=0)
Refer to SM1 for serial port mode selection.
Serial port Mode bit 1
SM0
0
0
1
1
Serial port Mode 2 bit/Multiprocessor Communication Enable bit
Clear to disable multiprocessor communication feature.
Set to enable multiprocessor communication feature in mode 2 and 3.
Reception Enable bit
Clear to disable serial reception.
Set to enable serial reception.
Transmitter Bit 8/Ninth bit to transmit in modes 2 and 3
Clear to transmit a logic 0 in the 9th bit.
Set to transmit a logic 1 in the 9th bit.
Receiver Bit 8/Ninth bit received in modes 2 and 3
Cleared by hardware if 9th bit received is a logic 0.
Set by hardware if 9th bit received is a logic 1.
Transmit Interrupt flag
Clear to acknowledge interrupt.
Set by hardware at the end of the 8th bit time in mode 0 or at the beginning of the
stop bit in the other
Receive Interrupt flag
Clear to acknowledge interrupt.
Set by hardware at the end of the 8th bit time in mode 0, see Figure 29. and
Figure 30. in the other modes.
SM2
5
SM1 Mode
0
1
0
1
Shift Register
8-bit UART
9-bit UART
9-bit UART
REN
4
Baud Rate
F
Variable
F
Variable
modes.
TB8
XTAL
XTAL
3
/12 (or F
/64 or F
XTAL
RB8
XTAL
2
/32
/6 in mode X2)
TI
1
4129K–CAN–01/05
RI
0