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 | ||
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Bit Number | Bit Mne- | Function | |
monic | |||
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7 | SMOD1 | Double Baud Rate Bit: | |
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| When set, doubles the baud rate for the second serial I/O port when timer 1 | |
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| is used and mode 1, 2 or 3 is selected in the SCON1 register. | |
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6 | SMOD0 | SCON1.7 Select: | |
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| When set, read/write accesses to SCON1.7 are to the FE1 bit. When | |
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| cleared, read/write accesses to SCON1.7 are to the SM0 bit. | |
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5 | RCLK1 | Second Serial I/O Port Receive Clock Bit: | |
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| Selects timer 2 overflow pulses (RCLK1 = 1) or timer 1 overflow pulses | |
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| (RCLK1 = 0) as the baud rate generator for the serial port modes 1 and 3. | |
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4 | TCLK1 | Second Serial I/O Port Transmit Clock Bit: | |
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| Selects timer 2 overflow pulses (TCLK = 1) or timer 1 overflow pulses | |
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| (TCLK1 = 0) as the baud rate generator for the serial port modes 1 and 3. | |
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3 - 0 | - | Reserved. | |
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10