Video Controller Operating Principles - Epson EPL-N2000 Service Manual

EPL-N2000 Service Manual
2.2.2.2 Video Controller Operation Principles
Print data and commands transmitted from the host computer through the network, parallel, or
optional I/F are read and then stored in the input buffer in DRAM. If the buffer size (which varies
depending on the SelecType setting) is increased, the host computer is released sooner.
Data and commands are then stored in the video RAM (the image buffer) memory area after being
processed in the video controller CPU, where the data is converted into print bitmap data (image
data). The size of the video RAM depends on the current size of the RAM memory and the
SelecType setting.
An error or warning for memory size occurs under the following conditions, and such problems
usually can be solved by changing buffer size or increasing RAM memory:
Bitmap data from the CPU is too complicated for the size of video RAM.
When data is complicated, the CPU cannot process it faster than it is transmitted to the
engine controller board.
Image data stored in video RAM is transmitted to the ASIC, where the BiRITech and PGI functions
manipulate the data. The data is then passed on to the engine controller as video data. The engine
controller processes the video data transmitted from the video controller. Engine mechanisms
driven by the PWB-A board then perform printing.
When an error occurs, the CPU in the engine controller detects it and sends status information to
the video controller, where the information is processed, and the corresponding error message and
the code are displayed on the Control panel.
Rev.A
Operating Principles
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