Advantech SOM-4450 Series, Design Manual

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Advantech SOM-ETX Design Guide
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 Type Description
OD This active low pulse is used to strobe the printer
data into the printer
C55 STB#
- None
LPT OD This active low output causes the printer to
automatically feed one line after each line is printed
C56 AFD#_DENSEL
Floppy OD Indicates whether a low (250/300Kb/s) or high
(500/1000Kb/s) data rate has been selected
LPT OD PD0 C80 PD0_INDEX#
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 C78 PD1_TRK0#
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 C76 PD2_WP#
Floppy OD This active-low Schmitt Trigger input signal senses
from the disk drive that a disk is write-protected
PD3
C74 PD3_RDATA#
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
OD PD4 C72 PD4_DSKCHG#
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 C68
Floppy OD None
LPT OD PD6 PD6_MOT0
Floppy OD These active-low outputs select motor drives 0
LPT OD PD7
Floppy
LPT
OD This active low signal indicates an error situation at
the printer
C60 ERR#_HDSEL#
Floppy 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
C64 INIT#_DIR#
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 SLIN#_STEP#
Floppy OD This active low output signal produces a pulse at a
software - programmable rate to move the head
during a seek operation
C84 ACK#_DSB# LPT OD This active low output from the printer indicates it
has received the data and is ready to receive new
data
I/O
LPT
Floppy
PD2
LPT OD
LPT
PD5
C62
C58 PD7_DSA#
OD When set to 0, this pin enable disk drive A
OD
Floppy
C70
94 Chapter 5 Carrier Board Design Guidelines