Specifications

REV.-A
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 mmputer to image data (the print image). The image data is then loaded
to RAM. Each line of data is processed sequentially. The CPU transfera 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 outputs the head drive
signal.
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RAM
CPU(IC21)
Input
Buffer
I
G/A E05A86
m ‘=-’”)
E05A50
Print Data
C6nvertor
------
Image
Image Data
Buffer
Transfer
IC or Circuit
TMP90C041
(IC2)
Date Latch and
Delay control
Printhrad
Figure 2-18. Data Flow
Table 2-5. Functions of the Main
IC and Circuits
Location
IC21
Icll
Functions
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. It also controls various
pwts of the printer mechanism, such as the motors.
This is a gate array consisting of three components
mnfigurd 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.
2-14