Intel 386 User Manual page 535

Intel386™ EX EMBEDDED MICROPROCESSOR USER'S MANUAL
Table A-2. Description of Signals Available at the Device Pins (Sheet 5 of 6)
Signal Type
SMI# ST System Management Interrupt:
Causes the device to enter System Management Mode.
SMI# is the highest priority external interrupt.
SMIACT# O System Management Interrupt Active:
Indicates that the processor is in System Management
Mode.
SRXCLK I/O SSIO Receive Clock:
In master mode, the baud-rate generator's output appears
on SRXCLK and can be used to clock a slave transmitter. In
slave mode, SRXCLK functions as an input clock for the
receiver.
SSIORX I SSIO Receive Serial Data:
Accepts serial data (most-significant bit first) into the SSIO.
SSIOTX O SSIO Transmit Serial Data:
Sends serial data (most-significant bit first) from the SSIO.
STXCLK I/O SSIO Transmit Clock:
In master mode, the baud-rate generator's output appears
on STXCLK and can be used to clock a slave receiver. In
slave mode, STXCLK functions as an input clock for the
transmitter.
TCK I Test Clock Input:
Provides the clock input for the test-logic unit.
TDI I Test Data Input:
Serial input for test instructions and data. Sampled on the
rising edge of TCK; valid only when either the instruction
register or a data register is being serially loaded.
TDO O Test Data Output:
Serial output for test instructions and data. TDO shifts out
the contents of the instruction register or the selected data
register (LSB first) on the falling edge of TCK. If serial
shifting is not taking place, TDO floats.
TMRCLK2 I Timer/Counter Clock Input:
TMRCLK1
An external clock source connected to the TMRCLK n pin
TMRCLK0
can drive the corresponding timer/counter.
TMRGATE2 I Timer/Counter Gate Input:
TMRGATE1
Can control the counter's operation (enable, disable, or
TMRGATE0
trigger, depending on the programmed mode).
TMROUT2 O Timer/Counter Output:
TMROUT1
Can provide the timer/counter's output. The form of the
TMROUT0
output depends on the programmed mode.
A-6
Name and Description
Multiplexed With
(Alternate
Function)
—
—
DTR1#
RI1#
RTS1#
DSR1
—
—
—
PEREQ
INT6
INT4
BUSY#
INT7
INT5
ERROR#
P3.1/INT8
P3.0/INT9