Data Transmission Timing - Fujitsu DL3800 User Manual

INTERFACE INFORMATION
D-6

Data Transmission Timing

In unidirectional mode (conventional Centronics interface), this
printer guarantees the received data when the Data and Data Strobe
signals from the computer have the following timing with respect to
the Busy and Acknowledge signals from the printer.
Data 1 to Data 8
Data Strobe
BUSY
Acknowledge
T1
In bidirectional mode (nibblemode), this printer can send data to the
computer. Data is sent in units of four bits (nibble) using four output
signal lines as data paths. The following outlines one byte of data sent
during reverse data transfer phase in nibble mode.
1284 Active
(from CPU)
Data Available (*)
X Flag
Ack Data Req
Printer Busy
Printer Clock
Host Busy
(from CPU)
* Data Available is assigned for the cable.
T4
T2 T3 T5 T6
T1, T2, T3 > 1 µs
T4 < 1 µs
0 µs < T5 < 3 µs
2 µs < T6 < 6 µs
Data bit 0 Data bit 4
Data bit 1 Data bit 5
Data bit 6
Data bit 2
Data bit 7
Data bit 3
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