Canon QY8-1360-000 Service Manual page 50

Part 2: Product Specifications
BJC-7100
Host Busy [Input]
Indicates that the host is ready to receive the data from the printer by making the
Host Busy signal Low in the reverse data transmission phase. After that, it goes
High when data is received from the printer to verify receiving data.
This signal changes to High in response to the PtrClk (ACKING) signal changing to
Low to change to the reverse data transmission phase.
Init
This signal is not used in nibble mode.
DataAvail [Output]
This signal outputs the data to be sent to the host computer in the reverse data
transmission phase. First, bit 0 of the transmission data is output, followed by bit
4.
Informs the host computer if there is reverse transmission data or not in the
negotiation phase. If data is ready to be sent to the host computer, this signal
changes to Low.
1284 Active (Input)
This signal confirms that the printer is an IEEE 1284-compatible device. This signal
goes High at the start of the negotiation phase and remains High in nibble mode to
indicate that the printer is operating in bidirectional mode. It changes to Low in the
termination phase.
ECP mode
HostClk [Input]
This is the signal used in handshaking with PeriphAck (BUSY) signal when data is
sent from the host computer to the printer.
This signal changes to Low when data has been output to the data bus (Data1 to 8)
This signal changes to High in response to the PeriphAck (BUSY) signal rising. It
remains High in the reverse data transmission phase.
Data 1 to 8 [Input/Output]
These are input data signals when data is sent from the host computer to the
printer.
In the reverse data transmission phase, these are output signals, and the printer
outputs data to the host computer using this data bus.
Periph Clk [Output]
This signal is always High when data is sent from the host computer to the printer.
In the reverse data transmission phase, this signal changes to Low to indicate that
data is output to the host computer. This signal changes to High in response to the
HostAck (AUTO FEED XT) signal changing to High.
Periph Ack [Output]
When data is sent from the host computer to the printer, this signal changes to Low
when the printer is ready to receive data.
When the data has been received from the host computer, this signal changes to
High.
In the reverse data transmission phase, this signal indicates if the information
output from the printer to the data bus is command information or data (Low:
Command information; High: data).
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