User's Manual

Interface
D-5
User's Manual
INTERFACE INFORMATION
Nibble Mode
Pin numbers 2 to 9, 15 to 31, and 33 to 35 are the same as the conventional
mode.
Pin Return Signal Direc- Description
No. Pin No. name tion
1 19 Host Clock Input This signal is set high when the
host requests the reverse data
transfer phase (nibble mode).
10 28 Printer Clock 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.
11 29 Printer Busy Output Reverse data transfer phase:
Data bit 3, data bit 7, then
forward path (host to printer)
busy status
12 30 Ack Data Req 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.
13 – X Flag Output Reverse data transfer phase:
Data bit 1, then data bit 5