
5.3.2Connector pin assignment
Connector (cable side): Shielded plug
MOLEX
1 | 18 |
19 | 36 |
(Cable side) (Male type)
Figure 5.7 Parallel interface connector (IEEE1284-C)
Signal definition:
Table 5.2 lists parallel interface signals and their functions.
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| Table 5.2 | Parallel interface signals | |||
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Connector | Return |
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| Signal |
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pin | line pin | Compati mode |
| Direction | Description | ||||
number | number |
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| Nibble mode |
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1 | 19 | Busy |
| Output | Data cannot be received when this signal is high, | ||||
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| e.g., if the buffer is full or an error occurs. |
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| Printer Busy |
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| Reverse data transfer phase: | |
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| Data bit 3, data bit 7, then forward path (host to |
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| printer) busy status |
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2 | 20 | Select (SLCT) |
| Output | This signal goes high when the printer is selected | ||||
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| (online), and goes low when the printer is deselected |
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| (offline). |
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| X Flag |
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| Reverse data transfer phase: | |
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| Data bit 1, then data bit 5 |
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3 | 21 |
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| Output | • Pulse signal indicating data reception completed |
Acknowledge |
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| (ACK) |
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| (or data reception enabled) status | ||
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| • Issued when the printer switches from offline to |
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| online |
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| Printer Clock |
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| Reverse data transfer phase: | |
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| This signal goes high when data being sent to the |
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| host is established. |
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| Reverse idle phase: |
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| This signal is set low then goes high to interrupt the |
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| host, indicating that data is available. |
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