k+5 V
z This is not a signal but a +5 V power supply voltage.
z The maximum current of 500 mA can be used for external equipement.
•IEEE1284 Active (Printer ← Host)
z The signal is used with the HostBusy signal, to request the data transfer in the IEEE1284 mode, or to request the end of the IEEE1284 mode.
z To request the data transfer in the IEEE1284 mode, the host sets the IEEE1284 Active signal and the HostBusy signal to high and low, respectively.
z To request the end of the IEEE1284 mode, the host sets the IEEE1284 Active signal and the HostBusy signal to low and high, respectively.
11HostBusy (Printer ← Host)
z Reverse data transfer phase: It indicates that the host can receive data from the printer by
setting the signal to low. After that, the host sets the signal to high, and sends the Ack indicating that the nibble data is received. When the signal is set to low after the reverse channel data transfer is performed, the interface phase changes to the idle phase. At that time, there is no available data on the printer.
zReverse idle phase: When this signal is set to high according to the low pulse of the PtrClk signal, the host enters the reverse data transfer phase again. If this signal is set to high when the IEEE1284 Active signal is low, the IEEE1284 idle phase stops, and the interface enters the compatible mode.
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