Explanation Ofthefunctionforeach Pcbs - Sanyo SFX-11 Service Manual

5-1. Explanation of the function for each PCB
1. M-1 (Main) PCB
This PCB contains CPU and all of the control circuits, the following
functions are included.
1)LSI so called FAX ENGINE (TC351 68F)
(1) 8-Bit CPU
(2) Modem :
- Modulation and Demodulation of signals
- Tone signal generation and detection
- Touch Tone Signal (DTMF) generation
- Pre-recorded Voice Prompt generation
- Melody generation (when conversation is put on hold)
(3) Codec :
- Coding and Decoding of image signal
(4) Image Signal Processor:
- Driving of CIS (Contact Image Sensor)
- Convert analog signal to digital signal (two or multi value)
- Reduction of image
(5) DMA (Direct Memory Access) Controller:
. Used when transferring the data from image signal processor to line
memory, from line memory to modem, to thermal head and
codec.
(6) Real Time Clock
(7) Stepping Motor Control
(8) Thermal head Control
(9) 1/0 ports control:
- NCU
- TEL
- Mechanism
- Operation Panel
- LCD control
2)1
-Mbits EPROM :
This PROM contains the program to control CPU.
3)64-Kbits SRAM (2-Pcs):
Used as line memory for memorizing image data temporarily or various
data memory.
4) Memory back-up control :
Used to keep the stored data of SRAM and Clock.
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5)NCU interface circuit:
This is a interface circuit for connecting the NCU and Modem.
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