Nibble Mode - Fujitsu Impact 4550 PRO User Manual

INTERFACE INFORMATION
D-4

Nibble Mode

Pin numbers 2 to 9, 15 to 31, and 33 to 35 are the same as the
conventional mode.
Pin Return
Signal Name
No. Pin No.
1 19 Host Clock
10 28 Printer Clock
11 29 Printer Busy
12 30 Ack Data Req
13 X Flag
−
INTERFACE INFORMATION
Direction Description
Input This signal is set high
when the host requests the
reverse data transfer phase
(nibble mode).
Output Reverse data transfer
phase:
This signal goes high
when data being sent to the
host is established.
Reverse idle phase:
This signal is set low then
goes high to interrupt the
host, indicating that data is
available.
Output Reverse data transfer
phase:
Data bit 3, data bit 7, then
forward path (host to
printer) busy status
Output Reverse data transfer
phase:
Data bit 2, then data bit 6
Reverse idle phase:
This signal is set high until
the host requests data and,
after that, follows the Data
Available signal.
Output Reverse data transfer
phase:
Data bit 1, then data bit 5
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