ETX-CN700
Appendix 1
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DSR1#, DSR2#
This active-low input is for serial port. Handshake signals are use to notify the UART that the
modem is ready to establish the communication link.
PS/2 Keyboard, PS/2 Mouse Signals
KBDAT
Bi-directional keyboard data signal.
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. Note: ensure that the FDD cable has the necessary twist so it is
recognised as Drive A:
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.
