Epson LG1-1070 Service Manual page 52

REV.-B
Table 2-5 lists the functions of the main components and circuits of the printer. The CPU converts the
print data sent from the host computer to image data (the print image). The image data is then loaded
to RAM. Each line of data is processed sequentially. The CPU transfers the print data to the printhead
drive circuit. The CPU sends the printhead drive pulse to the printhead drive circuit. The length of this
pulse corresponds to the printhead drive voltage. The head drive circuit then
signal.
TMP90C041
I
E05A50 4D
Data
Host
Computer
Pulse
Figure 2-18. Data Flow
Table 2-5. Functions of the Main IC and Circuits
Location
Receives data from the host computer and loads the data to the input
buffer in RAM (under interrupt processing control). Expands the input data
held in the buffer to create image data. Loads this image data to the
image buffer in RAM. Transfers the image data to the printhead drive
circuit. Also controls various parts of the PRINTER MECHANISM, such as
the motors.
This is a gate array consisting of three components configured on a
single chip:
Memory Management Unit
Handles CPU memory in ROM, RAM, and mask ROM, and assigns
addresses for other devices.
Parallel Interface (Parallel I/F)
Holds the parallel interface functions.
Reset Circuit
Contains the circuit that generates the RESET signal.
CPU
Print Data
Convertor
I I
S T K - 6 0 2 2 B
Data Latch
and
Data Output
Functions
2-14
outputs the head drive
RAM
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