Toshiba B-570 SERIES Owner's Manual page 54

3. OPTIONAL KIT
3.2 HIGH SPEED PC INTERFACE BOARD: B-4800-PC-QM
Command transfer and printing can be processed quickly by connecting a PC and the printer via a FIFO
(first-in first-out) IC on the high speed PC interface board. For details, refer to the specification for high
speed PC interface.
Configuration of interface
Signal description
Signal
Data FIFO
Status FIFO
Status request signal
Reset request signal
Image data transfer
request signal
Transmission control
When a command is sent from the PC to the printer:
Confirms that the image data transfer request bit has not been ON and the FIFO is vacant, then
writes a command to the FIFO.
When image data is sent from the PC to the printer:
Confirms that the image data transfer request bit has been ON, then writes the image data to
the FIFO.
When the printer transfers image data from the PC using DMA:
Turns the image data transfer request bit high-level to start DMA. When DMA transfer of all the
image data is completed, turns the image transfer request bit low-level.
When a status is sent from the printer to the PC: Writes a status to the FIFO.
Command
PC
Image data
Status request
Reset request
Direction
PC / Printer
PC , Printer
PC / Printer
PC / Printer
PC , Printer
3.2 HIGH SPEED PC INTERFACE BOARD : B-4800-QM
Data FIFO
Status FIFO
FIFO to transfer commands and image data. In
case of a command, FIFO data reading is
performed by the CPU. In case of image data,
reading is performed by DMA transfer.
FIFO to transfer status. The status for a status
autosending or for status request is written by the
BPE.
The PC turns this signal high-level to request for
a status. It is cleared when reading is performed.
The PC turns this signal high-level to request for
reset. It is cleared when reading is performed.
The printer turns this signal high-level when
ready for an image data transfer. When transfer
is completed, it is turned low-level.
The PC must not write the image data to the FIFO
until this signal turns high level. Also, the PC
must confirm that this signal is low-level for
sending a command.
3-2
Command
Printer
Image data
Status
Image data
Transfer request
Description
EM10-33006A
Fig. 3-2