Fujitsu DL6400 manual Data Transmission Timing, Figure C-1 Data transmission timing

DL6400/6600 Book Page 6 Friday, July 31, 1998 11:42 AM

Data Transmission Timing

Data

Transmission

Timing

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
	T4
T1	T2	T3	T5	T6
T1, T2, T3 > 1 μs
	T4 < 1 μs
0 μs< T5 < 3 μs
2 μs< T6 < 6 μs

Figure C–1 Data transmission timing

C-6 User’s Manual