IA186EM_04 Datasheet, PDF (25/133 Pages) InnovASIC, Inc – 8/16-Bit Microcontrollers

IA186EM/IA188EM
8/16-BIT Microcontrollers
Data Sheet
As of Production Version -03
RXIE (bit 10) – Receive Data Ready Interrupt Enable. This bit enables the generation of an interrupt
requests whenever the receive register contains valid data (RDR bit 1). The respective port does not
generate interrupts when this bit is 0. Interrupts continue to be generated as long as RDR and the
RXIE are 1.
LOOP (bit 9) – Loop-back. The serial port is placed into the loop-back mode when this bit is set.
BRK (bit 8) – Send Break. When this bit is set to 1, the txd pin is driven low, overriding any data that
may be in the course of being shifted out of the transmit shift register.
See the definitions of long and short break in the Serial Port Status register definition.
BRKVAL (bit 7) – Break Value. This is the ninth data bit transmitted when in modes 2 and 3. This bit
is cleared at each transmitted word and is not buffered. To transmit data with this bit set high, the
following procedure is recommended.
1. The TEMT bit in the serial port status register must go high.
2. Set the TB8 bit by writing it to the serial port control register.
3. Finally write the transmit character to the serial port transmit register.
Serial port 0 is a special case in that if this bit is 1, the associated pins are used for flow control
overriding the Peripheral Chip Select signals. This bit is 0 at reset.
PMODE (bits6:5) – Parity Mode. When this bit is set to 1, the txd pin is driven low overriding any
data that may be in the course of being shifted out of the transmit shift register.
See the definitions of long and short break in the Serial Port Status register definition.
WLGN (bit 4) – Word Length. The number of bits transmitted or received in a frame is determined by
the value of this bit. When this bit is 0, the number of data bits in a frame is 7 whereas when this bit is
1 the number of data bits in a frame is 8. This bit is 0 at reset.
STP (bit 3) – Stop Bits. This bit specifies the number of stop bits used to indicate the end of a frame.
When this bit is 0, the number of stop bits is 1. When it is 1, the number of stop bits is 2. This bit is 0
at reset.
TMODE (bit 2) – Transmit Mode. The transmit section of the serial port is enabled when this bit is 1
and disabled when this bit is 0.
RSIE (bit 1) – Receive Status Interrupt Enable. When an exception occurs during data reception an
interrupt request is generated if enabled by this bit (RSIE = 1). Interrupt requests are made for the
error conditions listed (BRK, OER, PER, and FER) in the serial port status register. This bit is 0 at
reset.
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