2–26
Table 2–22. Parallel Port Connections (J15)
J15
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, ke ep the cable betw een th e board and the
device it drives to 10 feet or less in length.
IEEE-1284-compliant Cables
Using the paralle l port fo r high- speed data transfe r in ECP/EPP mod es require s special cablin g for
maximum reliability.
Some of the paramete rs 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 16 MHz
• The wire-to-wire crosstalk should be no greater than 10%