Intel 8XC196MC, 8XC196MD, 8XC196MH manual Serial Port Modes

8XC196MC, MD, MH USER’S MANUAL

Table 7-2. Serial Port Control and Status Registers (Continued)

Mnemonic	Address	Description
PI_MASK	1FBCH	Peripheral Interrupt Mask
		This register enables and disables multiplexed peripheral interrupts.
		Setting an SPx bit enables a serial port receive error interrupt;
		clearing the bit disables (masks) the interrupt.
PI_PEND	1FBEH	Peripheral Interrupt Pending
		This register indicates pending multiplexed peripheral interrupts.
		When set, an SPx bit indicates a pending serial port receive error
		interrupt.
SBUF0_RX	1F80H	Serial Port x Receive Buffer
SBUF1_RX	1F88H	This register contains data received from the serial port.
SBUF0_TX	1F82H	Serial Port x Transmit Buffer
SBUF1_TX	1F8AH	This register contains data that is ready for transmission. In modes
		1, 2, and 3, writing to SBUFx_TX starts a transmission. In mode 0,
		writing to SBUFx_TX starts a transmission only if the receiver is
		disabled (SPx_CON.3 = 0).
SP0_BAUD	1F84H,1F85H	Serial Port x Baud Rate
SP1_BAUD	1F8CH,1F8DH	This register selects the serial port baud rate and clock source. The
		most-significant bit selects the clock source. The lower 15 bits
		represent the BAUD_VALUE, an unsigned integer that determines
		the baud rate.
SP0_CON	1F83H	Serial Port x Control
SP1_CON	1F8BH	This register selects the communications mode and enables or
		disables the receiver, parity checking, and ninth-bit data transmis-
		sions. The TB8 bit is cleared after each transmission.
		For mode 4, this register also selects the direction (input or output)
		of the SCLKx# signal.
SP0_STATUS	1F81H	Serial Port x Status
SP1_STATUS	1F89H	This register contains the serial port status bits. It has status bits for
		receive overrun errors (OE), transmit buffer empty (TXE), framing
		errors (FE), transmit interrupt (TI), receive interrupt (RI), and
		received parity error (RPE) or received bit 8 (RB8). Reading
		SPx_STATUS clears all bits except TXE; writing a byte to
		SBUFx_TX clears the TXE bit.

7.3SERIAL PORT MODES

The serial port has both synchronous and asynchronous operating modes for transmission and re- ception. This section describes the operation of each mode.

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