Serial I/O Port Signals And Registers - Intel 8XC196NT User Manual

8XC196NT USER'S MANUAL
7.2

SERIAL I/O PORT SIGNALS AND REGISTERS

Table 7-1 describes the SIO signals and Table 7-2 describes the control and status registers.
Port Serial Port
Pin Signal
P2.0 TXD
P2.1 RXD
P6.2 T1CLK
Table 7-2. Serial Port Control and Status Registers
Mnemonic Address
INT_MASK1 0013H
INT_PEND1 0012H
P2_DIR 1FCBH
P2_MODE 1FC9H
P2_PIN 1FCFH
7-2
Table 7-1. Serial Port Signals
Serial
Port
Signal
Type
O Transmit Serial Data
In modes 1, 2, and 3, TXD transmits serial port output data. In mode 0,
it is the serial clock output.
I/O Receive Serial Data
In modes 1, 2, and 3, RXD receives serial port input data. In mode 0, it
functions as an input or an open-drain output for data.
I Timer 1 Clock
External clock source for the baud-rate generator input.
Interrupt Mask 1
Setting the TI bit enables the transmit interrupt; clearing the bit
disables (masks) the interrupt.
Setting the RI bit enables the receive interrupt; clearing the bit
disables (masks) the interrupt.
Interrupt Pending 1
When set, the TI bit indicates a pending transmit interrupt.
When set, the RI bit indicates a pending receive interrupt.
Port 2 Direction
This register selects the direction of each port 2 pin. Clear P2_DIR.1
to configure RXD (P2.1) as a high-impedance input/open-drain
output, and set P2_DIR.0 to configure TXD (P2.0) as a comple-
mentary output.
Port 2 Mode
This register selects either the general-purpose input/output function
or the peripheral function for each pin of port 2. Set P2_MODE.1:0
to configure TXD (P2.0) and RXD (P2.1) for the SIO port.
Port 2 Pin State
Two bits of this register contain the values of the TXD (P2.0) and
RXD (P2.1) pins. Read P2_PIN to determine the current value of the
pins.
Description
Description