Sharp FACSIMILE FO-4500 Service Manual page 104

FO-4500H
Code Terminal No.
CLKI
CLKX
CKTST1
CLKMOD
CKTST0
CLKO
CKTST2
Code Terminal No.
RTCH
RTCL
(8) Page memory block
The page memory block is composed of one DRAM of 1M × 16 bits,
being commonly used as the image memory. The memory is divided
into the page memory for the scanner and the page memory for
printing.
The page memory for scanner is composed of the whole area of IC10
and the partical area of IC9 and IC11. The image data of approx. one
page (except in the super fine mode) of the draft read with the scan-
ner can be stored.
They are stored until they are contracted by CODEC.
The page memory for printing is composed of the remaining areas of
IC9 and IC10 and can store approx. one page of the image data
decoded by CODEC. The data are stored until they are transferred to
PCU with the gate array (B) and printed.
I/O
19 I
20 O
1 I
40 I
41 I
21 O
80 I
I/O
60 O
61 O
Quartz oscillation input terminal and external clock input terminal
Quartz oscillation output terminal
Low pass filter terminal of PLL circuit
Connected to capacitor (1000pF) and resistor (10kΩ) through GND.
Terminal to switch quartz oscillation connection or external clock input mode.
"0": Quartz oscillation
"1": External clock
Fix at "LOW" level.
Clock output terminal. Rectangular wave which is synchronous with the internal
clock of IDP201 is output.
Fix at "LOW" level.
Number of transfers of EOL detected by IDP201 during RTC receiving is
reflected at the terminal.
5 – 14
Name and function
Name and function