Ieee-1284-compliant cables, Ieee-1284-compliant cables –21 – Ampro Corporation LITTLE BOARD 5001451A User Manual
Page 39
Little Board P6d Module
2-21
Table 2-20. Parallel Port Connections (J9)
Pin #
Signal Name
Function
In/Out
DB25 Pin
1
STB*
Output Data Strobe
Out
1
3
PD 0
LSB Of Printer Data
I/O
2
5
PD 1
Printer Data 1
I/O
3
7
PD 2
Printer Data 2
I/O
4
9
PD 3
Printer Data 3
I/O
5
11
PD 4
Printer Data 4
I/O
6
13
PD 5
Printer Data 5
I/O
7
15
PD 6
Printer Data 6
I/O
8
17
PD 7
MSB Of Printer Data
I/O
9
19
ACK*
Character Accepted
In
10
21
BUSY
Cannot Receive Data
In
11
23
PE
Out of Paper
In
12
25
SLCT
Printer Selected
In
13
2
AUTOFD*
Autofeed
Out
14
4
ERROR
Printer Error
In
15
6
INIT*
Initialize Printer
Out
16
8
SELIN*
Selects Printer
Out
17
26
KEY
Key Pin
N/A
Note
For maximum reliability, keep the cable between the board and the
device it drives to 10 feet or less in length.
IEEE-1284-compliant Cables
Using the parallel port for high-speed data transfer in ECP/EPP modes requires special cabling for
maximum reliability.
Some of the parameters for a compliant IEEE-1284 cable assembly include:
All signals are twisted pair with a signal and ground return
Each signal and ground return should have a characteristic unbalanced impedance of 62 +/- 6 ohms
within a frequency band of 4 to 16MHz
The wire-to-wire crosstalk should be no greater than 10%
Please refer to the IEEE-1284 standard for the complete list of requirements for a compliant cable
assembly, including recommended connectors