Data Transmission Timing - Fujitsu DL6400Pro User Manual

Data Transmission Timing

Data
Transmission
Timing
C-6
The 6400 Pro/6600 Pro uses a bi-directional parallel interface
complying with IEEE 1284. This interface is also compatible with the
conventional Centronics interface. Data transfer from host to print is
performed according to Centronics standard, called compatible mode.
Data transfer from printer to host, it is performed according to the
IEEE 1284 standard, called nibble mode.
In compatible mode, the printer receives data from the computer in
handshaking mode based on the Busy and Acknowledge signals from
the printer and the Data Strobe signal from the computer. For the Data
Strobe and Acknowledge signals, the timing of the Busy signal must be
as shown in Figure C-1.
To send data from the printer to the host, the interface enters the
nibble mode where data is sent in units of four bits (nibble) using the
four output signal lines as data paths. The data transfer sequence in
nibble mode involves negotiation phase, reverse idle phase, reverse data
transfer phase, and termination phase. Figure C-2 shows the reverse
data transfer phase where data is sent.
Compatible mode (data transfer from host to printer):
Data 1 to Data 8
Data Strobe
BUSY
Acknowledge
Figure C–1 Data transmission timing
T4
T1 T2 T3
T5 T6
T1, T2, T3 > 1 s
T4 < 1 s
0 s< T5 < 3 s
2 s< T6 < 6 s
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