Canon C5000 - MultiPASS Color Inkjet Printer, Service Manual, Page: 200 / 221

Chapter 2: Technical Reference
2.3
Data Flow
1)
Interface
Character codes, control codes, and image data conforming to the printer’s character table
are sent to the interface from the computer. The data are received when the printer is in
on-line standby, or when the carriage changes directions during printing.
2)
Input
buffer
Data received from the interface are stored in the printer DRAM’s built in input (reception)
buffer
3) Data
analysis and printer buffer
The MPU analysis the data stored in the input buffer, and printing image data for each
nozzle of the cartridge are stored in the printer DRAM’s built-in print buffer.
If there are character data, the ROM font image data stored in the print
buffer. Control codes are used for switching print modes, etc. The image data are already
formatted for each nozzle of the BJ cartridge, and stored as is in the print buffer.
4) Printing
When control codes with a etc, print start function are processed, and the print
buffer becomes full, the image data stored in the printer buffer are sent to the cartridge
and printed out.
Character Code: = 42 Hex.
Character Code: “J” 4A Hex
Control Code: ESC (Select Image Mode)
Hex. Hex cd>
(DRAM)
Character “BJ”
Image
Figure 2-2 Data Flow (image)
2-3