Intel 8xC251TQ, 8xC251TB, 8XC251SA, 8XC251SP, 8XC251SQ, 8XC251SB Bit Number Bit Mne Function Monic

8xC251Tx Hardware Description

3.2.2SBUF1

Address: 9BH

Reset Value: xxxx xxxxB

To send serial data, software writes a byte to SBUF1 and to receive serial data, software reads from SBUF1.

3.2.3SADDR1

Address: AAH

Reset Value: 0000 0000B

Slave Individual Address Register1 (SADDR1) contains the device’s individual address for multiprocessor communications.

3.2.4SADEN1

Address: BAH

Reset Value: 0000 0000B

Mask Byte Register 1 (SADEN1) masks bits in the SADDR1 register to form the devices given address for multiprocessor communications.

3.2.5BGCON

Address: 8FH

Reset Value: 0000 xxxxB

	Table 7. BGCON Special Function Register Definitions
Bit Number	Bit Mne-	Function
	monic
7	SMOD1	Double Baud Rate Bit:
		When set, doubles the baud rate for the second serial I/O port when timer 1
		is used and mode 1, 2 or 3 is selected in the SCON1 register.
6	SMOD0	SCON1.7 Select:
		When set, read/write accesses to SCON1.7 are to the FE1 bit. When
		cleared, read/write accesses to SCON1.7 are to the SM0 bit.
5	RCLK1	Second Serial I/O Port Receive Clock Bit:
		Selects timer 2 overflow pulses (RCLK1 = 1) or timer 1 overflow pulses
		(RCLK1 = 0) as the baud rate generator for the serial port modes 1 and 3.
4	TCLK1	Second Serial I/O Port Transmit Clock Bit:
		Selects timer 2 overflow pulses (TCLK = 1) or timer 1 overflow pulses
		(TCLK1 = 0) as the baud rate generator for the serial port modes 1 and 3.
3 - 0	-	Reserved.

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