Sharp QD-101MM, Service Manual, Page: 14 / 66

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Fig.6 PLL Circuit
6. MEMORY CIRCUIT
BLOCK DIAGRAM is shown in Fig.2.
6.1.Field memory writing
When data sent from the signal selector is written into the field memory(IC103~105), FWCK
(clock slightly later than CLK) generated from the memory controller in IC100 is used.
6.2.Field memory reading
The clock (FRCK) and control signals which are generated in the field memory reading signal
generating circuit in IC100 are used to read data from the field memory.
Reading is asynchronous with writing. In the ordinary mode, data written into the field memory
are color-compensated and are sent to LCD.
In the enlargement mode, the enlargement control signal is sent to the field memory from the
field memory writing/reading signal generating circuit in IC100 to make the enlargement display
possible.
6.3.Menu, message display memory
The menu and message display is stored in the ROM area of IC400(MPU).
When the menu button is first pressed, MPU will write data and address into VRAM (IC108, 111)
via IC100. Moreover, VRAM data is read via IC100.
The data is sent to LCD at the timing of LCD.
Fig. 8 Memory Circuit Block Diagram
VRAM
IC100
ROM MPU
LCD FIELD MEMORY
menu and
message data
display data
IC108, 111
IC103~105