Thefollowing figure showsthe data flowfrom the host computer tothe printhead. Datasent from the host
computer is converted toimage data and transmitted tothe printhead throughthe gate array.
Thefollowing table lists theeach function of the maincomponents of the C166 MAIN board.
Table 2-7 Functionsof the Main Board
IC Location Function
CPU IC1
Receives datafrom the hostcomputer and sends it to theinput buffer
in RAM (under interrupt processing control). Extendsthe 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.
Gate Array IC2
Controls the functions below:
•Controls output data from the internalblock
•Memory management
•Address latch of the address/data bus from the CPU
•Clock control unit
•Bit manipulation
•Interface control
•Expanded parallel port
•Printhead control
•Motor control
EEPROM IC8 An electrically writable and erasable ROM used to hold such
information as the TOFposition and bidirectional adjustment value.
ROM IC 3 The ROM contains the program that runs the CPU and holds the
character design(also called the character generator).
RAM IC 5 The RAM containsthe CPU working areaand the buffers
SLA7024M IC 12 Drive circuit for the CR motor
UDN2917EB IC 11 Drive circuit for the PF motor
Host
Computer
CPU
TMP96C041AF
RAM
Gate Array
E05B13
Printhead drive
circuite
Input
Buffer
Image
Buffer
Line Edit
Buffer
Print data
conversion 1
Print data
conversion 2
Data latch
and
data output
Image data
transfer
Parallel I/F
Option I/F
Figure 2-31 DataFlow
FX-2170 ServiceManual Operating Principles
Rev.A 2-23