BJC-4300Part 4: Technical Reference
2.1.2 Nibble mode
In nibble mode, the printer transfers data twice to the host computer in 4-bit units.
The data is transferred with the F?trClk signal and HostBusy signal handshakes.
After the printer contlrms that the HostBusy signal is low, it prepares S-bit data,
lowers the FTrClk signal and outputs the lower 4.bits along the control signal line.
After the PtrClk signal is low, the host computer receives the data and raises the
HostBusy signal. Next, after the printer cont3rms that the HostBusy signal is low for a
second time, it outputs the upper 4-bits along the control signal line. If there is no
data to be sent to the host computer after the HostBusy signal is high, the DataAvail
signal becomes high and the printer stands by for the next data transfer.
Figure 4-8 Interface Timing (Nibble Mode)
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