Panasonic KX-FC255CX-S, Service Manual

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KX-FC255CX-S
6.3. Control (Facsimile) Section
6.3.1. ASIC (IC10)
This custom IC is used for the general FAX operations.
1. CPU:
This model uses a Z80 equivalent to the CPU operating
at 12 MHz. Most of the peripheral functions are performed
by custom-designed LSIs. Therefore, the CPU only works
for processing the results.
2. RTC:
Real Time Clock
3. DECODER:
Decodes the address.
4. ROM/RAM I/F:
Controls the SELECT signal of ROM or RAM and the
bank switching.
5. CIS I/F:
Controls the document reading.
6. IMAGE DATA RAM:
This memory is programmed into the ASIC and uses 8
KB for the image processing.
7. THERMAL HEAD I/F:
Transmits the recorded data to the thermal head.
8. MOTOR I/F:
Controls the transmission motor which feeds the docu-
ment.
Controls the receiving motor which feeds the recording
paper.
9. OPERATION PANEL I/F:
Serial interface with Operation Panel.
10. I/O PORT:
I/O Port Interface.
Note*:
This memory is incorporated into the ASIC (IC10) and used for the image processing.
Fig. A shows the memory map of the Image Data RAM.
6.3.2. Flash Memory (IC16)
This 512KB ROM (FLASH MEMORY) carries a common area of 32KB and bank areas which each have 8KB (BK4~BK63). The
addresses from 0000H to 7FFFH are for the common area and from 8000H to 9FFFH are for the bank areas.
6.3.3. Dynamic RAM (IC17)
The DRAM serves as CPU and receives memory.
The address is F200H~F3FFH (DRAM access window 1) and F600H~F7FFH (DRAM access window 2).