Canon QY8-1360-000 Firmware, Compatible mode, 6 Interface Timing Compatible Mode, BJC-7100

Part 4: Technical Reference BJC-7100

2.FIRMWARE

2.1Interface

The printer is equipped with an IEEE1284-compatible bidirectional parallel interface. This interface supports compatible mode, nibble mode, and ECP mode.

Compatible Mode

Selectin=High

Autofd=Low

Compatible Mode:

In compatible mode, signals are sent in one direction only, from the host PC to the printer, as with the standard Centronics interface. This is the default mode when the printer is turned on.

Negotiation:

Negotiation is the procedure by which the printer interface adjusts to bidirectional mode.

Negotiation	1000 0000 *	Extensibility Link
Extensibility
request analysis
	0001 0000 *
0000	0000 *		* Value of extensibility
Nibble Mode	ECP Mode		request
			Rejection

Selectin=Low Extensibility Link:

This is a part of the negotiation phase, entered when the value

Terminationof the received extensibility request is (1000 0000). The bidirectional mode and device ID, etc., are exchanged in this phase.

Termination:

The interface returns from nibble mode or ECP mode to compatible mode in this phase.

Figure 4-5 Bidirectional Centronics Specifications Selection Sequence

2.1.1 Compatible mode

In compatible mode, the parallel interface sends data in 8-bit units.

Data is sent using handshaking based on the DATA STROBE, BUSY, and ACKNLG signals.

When data (Data 1 to 8) and the DATA STROBE signal are input from the host PC, the printer controller, which controls the parallel interface, outputs a BUSY signal and latches the data signals as DATA STROBE falls. After the BUSY signal has been output, the printer controller fetches the latched data via the DRAM bus to the receive buffer in the DRAM. After writing the data to the receive buffer in the DRAM, the printer controller outputs an ACKNLG signal, sets the BUSY signal "Low", and waits to receive the next data from the host PC.

The BJC-7100 can reduce the response time by the operation in the printer driver. This achieves faster printing, however, this may not work with some host computers.

0.5μs 0.5μs 0.5μs Min. Min. Min.

Data 1-8

STROBE

Min.0.8μs

BUSY

ACKNLG

4ms (When HS mode is invalid)

Figure 4-6 Interface Timing (Compatible Mode)

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