BCT-ETX-C3-XXX
S
INGLE
B
OARD
C
OMPUTER
I
NSTALLATION
KBCLK
Keyboard clock signal.
MSDAT
Bi-directional mouse data signal.
MSCLK
Mouse clock signal.
IRDA (SIR) Signals
IRTX, IRRX
Infrared transmit and receive pins.
Parallel Port Signals
The parallel port signals require external termination components. The parallel port has two alternative operating
modes: parallel port and floppy disk. If the parallel port is used in parallel port mode, floppy disk support is not
available via the parallel port. The LPT/FLPY# pin, which switches the parallel port modes, is sensed only at
boot and cannot be changed dynamically. If simultaneous floppy drive and parallel support is needed, an external
floppy controller may be incorporated in the baseboard design.
LPT/FLPY#
This ETX input signal selects whether the parallel port pins will implement parallel port or floppy support
functionality. There is an internal pullup on this signal. If this signal is high or unconnected, the following
parallel port pin functions are in effect:
STB#
This active-low signal is used to strobe the printer data into the printer.
AFD#
This active-low output tells the printer to automatically feed the next single line after each preceding line has
been printed.
PD[0..7]
This bi-directional parallel data bus is used to transfer information between the CPU and the peripherals.
ERR#
This active-low signal indicates an error situation has occurred at the printer.
INIT#
This active-low signal is used to initiate the printer when low.
SLIN#
This active-low signal selects the printer.
ACK#
This active-low output from the printer indicates that it has received the previous data and that it is ready to
receive new data.
BUSY#
This signal indicates that the printer is busy and not ready to receive new data.
PE
This signal indicates that the printer is out of paper.
SLCT#
This active-high output from the printer indicates that its power is on.
Floppy Signals
ETX modules support only a single floppy drive over the parallel port interface. When operating in floppy disk
mode, the parallel port is not available.
LPT/FLPY#
This ETX input signal selects whether the parallel port pins will implement parallel port or floppy support
functionality. There is an internal pullup on this signal. If this signal is low, the following floppy support
functions are supported over the parallel port pins:
DENSEL
Indicates whether a low (250/300Kb/s) or high (500/1000Kbs) data rate has been selected.
INDEX#
This active-low Schmitt Trigger input signal is asserted by the disk drive when the diskette index hole is sensed.
TRK0#
This active-low Schmitt Trigger input signal is asserted by the disk drive when the head is positioned over the
outermost track.
WP#
This active-low Schmitt Trigger input signal is asserted by the disk drive when a disk is write-protected.