Serial I/O Port Signals And Registers - Intel 8XC196K Series User Manual

8XC196K x , J x , CA USER'S MANUAL
An independent, 15-bit baud-rate generator controls the baud rate of the serial port. Either XTAL1
or T1CLK can provide the clock signal. The baud-rate register (SP_BAUD) selects the clock
source and the baud rate.
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
†
The T1CLK pin is not implemented on the 8XC196CA, JQ, JR, JT, JV devices. XTAL1 must provide
the serial port clock.
Table 7-2. Serial Port Control and Status Registers
Mnemonic Address
INT_MASK1
INT_PEND1
†
Except as otherwise noted, write zeros to the reserved bits in these registers.
††
The T1CLK pin is not implemented on the 8XC196CA, JQ, JR, JT, JV devices. XTAL1 must provide the
serial port clock.
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.
0013H 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.
0012H Interrupt Pending 1
When set, the TI bit indicates a pending transmit interrupt.
When set, the RI bit indicates a pending receive interrupt.
Description
†
Description