Signal Description - Advantech SOM-ETX Series Design Manual

5.10.1

Signal Description

Table 5.20 shows SOM-ETX LPT/FDD signals, including pin number, signals, I/0,
power plane, terminal resistors, damping resistors and descriptions.
Table 5.20 LTP/Floppy Signal Descriptions
Pin Signal
C55 STB#
C56 AFD#_DENSEL
C80 PD0_INDEX#
C78 PD1_TRK0#
C76 PD2_WP#
C74 PD3_RDATA#
C72 PD4_DSKCHG#
C68 PD5
C62 PD6_MOT0
C58 PD7_DSA#
C60 ERR#_HDSEL#
C64 INIT#_DIR#
C70 SLIN#_STEP#
C84 ACK#_DSB#
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Advantech SOM-ETX Design Guide
Type I/O Description
LPT OD This active low pulse is used to strobe the printer
data into the printer
Floppy - None
LPT OD This active low output causes the printer to
automatically feed one line after each line is printed
Floppy OD Indicates whether a low (250/300Kb/s) or high
(500/1000Kb/s) data rate has been selected
LPT OD PD0
Floppy OD This active low Schmitt Trigger input signal senses
from the disk drive that the head is positioned over
the beginning of a track, as marked by an index
hole
LPT OD PD1
Floppy OD This active low Schmitt Trigger input signal senses
from the disk drive that the head is positioned over
the outermost track
LPT OD PD2
Floppy OD This active-low Schmitt Trigger input signal senses
from the disk drive that a disk is write-protected
LPT OD PD3
Floppy OD The active-low, raw data read signal from the disk
is connected here. Each falling edge represents a
flux transition of the encoded data
LPT OD PD4
Floppy OD This disk interface input indicates when the disk
drive door has been opened. This active-low signal
is read from bit D7 of location base+
LPT OD PD5
Floppy OD None
LPT OD PD6
Floppy OD These active-low outputs select motor drives 0
LPT OD PD7
Floppy OD When set to 0, this pin enable disk drive A
LPT OD This active low signal indicates an error situation at
the printer
Floppy OD This active low output determines which disk drive
head is active. Low = Head 0, high (open) =Head 1
LPT OD This active low signal is used to initiate the printer
when low
Floppy OD This active low output determines the direction of
the head movement (low = step-in, high = step-out).
LPT OD This active low signal selects the printer
Floppy OD This active low output signal produces a pulse at a
software - programmable rate to move the head
during a seek operation
LPT OD This active low output from the printer indicates it
has received the data and is ready to receive new
data
Chapter 5 Carrier Board Design Guidelines